Page 36 | Best Free Application Development Software of 2026

XAML

Microsoft

XAML is a declarative markup language. As applied to the .NET Core programming model, XAML simplifies creating a UI for a .NET Core app. You can create visible UI elements in the declarative XAML markup, and then separate the UI definition from the run-time logic by using code-behind files that are joined to the markup through partial class definitions. XAML directly represents the instantiation of objects in a specific set of backing types defined in assemblies. This is unlike most other markup languages, which are typically an interpreted language without such a direct tie to a backing type system. XAML enables a workflow where separate parties can work on the UI and the logic of an app, using potentially different tools. When represented as text, XAML files are XML files that generally have the .xaml extension. The files can be encoded by any XML encoding, but encoding as UTF-8 is typical.

Starting Price: Free

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Windows Forms

Microsoft

Welcome to the Desktop Guide for Windows Forms, a UI framework that creates rich desktop client apps for Windows. The Windows Forms development platform supports a broad set of app development features, including controls, graphics, data binding, and user input. Windows Forms features a drag-and-drop visual designer in Visual Studio to easily create Windows Forms apps. Windows Forms is a UI framework for building Windows desktop apps. It provides one of the most productive ways to create desktop apps based on the visual designer provided in Visual Studio. Functionality such as drag-and-drop placement of visual controls makes it easy to build desktop apps. With Windows Forms, you develop graphically rich apps that are easy to deploy, update, and work while offline or while connected to the internet. Windows Forms apps can access the local hardware and file system of the computer where the app is running.

Starting Price: Free

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WinUI

Microsoft

The Windows UI Library (WinUI) is a native user experience (UX) framework for both Windows desktop and UWP applications. By incorporating the Fluent Design System into all experiences, controls, and styles, WinUI provides consistent, intuitive, and accessible experiences using the latest user interface (UI) patterns. With support for both desktop and UWP apps, you can build with WinUI from the ground up, or gradually migrate your existing MFC, WinForms, or WPF apps using familiar languages such as C++, C#, Visual Basic, and Javascript (via React Native for Windows).

Starting Price: Free

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Apache ServiceComb

ServiceComb

Open-source, full-stack microservice solution. With out-of-the-box, high performance, compatible with popular ecology, and multi-language support. Service contract guarantee based on OpenAPI. One-click scaffolding, out of the box, speeds up the building of microservice applications. The ecological extension supports multiple development languages such as Java/Golang/PHP/NodeJS. Apache ServiceComb is an open-source solution for microservices. It consists of multiple components that can be flexibly adapted to different scenarios through the combination of components. This guide can help you get started quickly with Apache ServiceComb, which is the best place to start trying for first-time users. To decouple the programming and communication models, so that a programming model can be combined with any communication models as needed. Application developers only need to focus on APIs during development and can flexibly switch communication models during deployment.

Starting Price: Free

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Kong Mesh

Kong

Enterprise service mesh based on Kuma for multi-cloud and multi-cluster on both Kubernetes and VMs. Deploy with a single command. Connect to other services automatically with built-in service discovery, including an Ingress resource and remote CPs. Support across any environment, including multi-cluster, multi-cloud and multi-platform on both Kubernetes and VMs. Accelerate initiatives like zero-trust and GDPR with native mesh policies, improving the speed and efficiency of every application team. Deploy a single control plane that can scale horizontally to many data planes, or support multiple clusters or even hybrid service meshes running on both Kubernetes and VMs combined. Simplify cross-zone communication using an Envoy-based ingress deployment on both Kubernetes and VMs, as well as the built-in DNS resolver for service-to-service communication. Built on top of Envoy with 50+ observability charts out of the box, you can collect metrics, traces, and logs of all L4-L7 traffic.

Starting Price: $250 per month

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Network Service Mesh

A common flat vL3 domain allowing DBs running in multiple clusters/clouds/hybrid to communicate just with each other for DB replication. Workloads from multiple companies connecting to a single ‘collaborative’ Service Mesh for cross company interactions. Each workload has a single option of what connectivity domain to be connected to, and only workloads in a given runtime domain could be part of its connectivity domain. In short: Connectivity Domains are Strongly Coupled to Runtime Domains. A central tenant of Cloud Native is Loose Coupling. In a Loosely Coupled system, the ability for each workload to receive service from alternative providers is preserved. What Runtime Domain a workload is running in is a non-sequitur to its communications needs. Workloads that are part of the same App need Connectivity between each other no matter where they are running.

Starting Price: Free

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AWS App Mesh

Amazon Web Services

AWS App Mesh is a service mesh that provides application-level networking to facilitate communication between your services across various types of computing infrastructure. App Mesh offers comprehensive visibility and high availability for your applications. Modern applications are generally made up of multiple services. Each service can be developed using various types of compute infrastructure, such as Amazon EC2, Amazon ECS, Amazon EKS, and AWS Fargate. As the number of services within an application grows, it becomes difficult to pinpoint the exact location of errors, redirect traffic after errors, and safely implement code changes. Previously, this required creating monitoring and control logic directly in your code and redeploying your services every time there were changes.

Starting Price: Free

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xmlGrid.net

Load your XML file to the online XML editor. You can choose any of the methods listed in the menu: paste the data directly to the Input Box, open the file from your local file system or get it from internet By URL. After the XML data is loaded, it will be displayed in a hierarchical XML Grid which allows you to easily navigate the tree structure. You can add, edit, or delete any node or brach of the tree structure. If you want to save the edited XML document you can choose the Save function from the menu, the XML data will be displayed in a nice formatted text. Load your XML data into the Online Editor. The XML code will be validated against W3C XML 1.0 specifications.

Starting Price: Free

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XML Notepad

Microsoft

XML Notepad provides a simple intuitive User Interface for browsing and editing XML documents. Tree View synchronized with Node Text View for quick editing of node names and values. Drag/drop support for easy manipulation of the tree, even across different instances of XML Notepad and from the file system. Good performance on large XML documents, loading a 3mb document in about one second. Instant XML schema validation while you edit with errors and warnings shown in the task list window. Intellisense based on expected elements and attributes and enumerated simple type values. Support for custom editors for date, dateTime and time datatypes and other types like color. Handy nudge tool bar buttons for quick movement of nodes up and down the tree. Handy "XML statistics" tool to summarize info about your XML documents.

Starting Price: Free

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Liquid Studio

Liquid Technologies

Liquid Studio provides an advanced toolkit for XML and JSON development along with Web Service Testing and Data Mapping and Data Transformation tools. The Development Environment contains a complete set of tools for designing XML and JSON data structures and schemas. These tools provide editing, validating and advanced transformation capabilities. For novice or expert, the intuitive interface and comprehensive features will help you save time and money delivering a successful project. Visualize and edit an abstracted view of your XML schema(XSD) using an intuitive user interface, and validate your XSD against the W3C standards.Includes split graphical and text views, intellisense, syntax highlighting, drag and drop, copy and paste, and multi-step undo/redo. Visualize and edit an abstracted view of your JSON schema using an intuitive user interface, and validate your JSON Schema against the IETF standards.

Starting Price: $149 one-time payment

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SIMQIN

Today, XML is a widespread standard in multi-media and cross-platform publishing of technical documentation. Many editing programs, management systems and publication tools, as well as many industry standards, are now based on XML. Nevertheless, XML has not yet been able to break through in all areas, because the format has a very clear separation between the structure and the layout of documents. Editors still prefer to work with word processors such as Microsoft Word: here, the text and the document layout are created almost simultaneously and can be immediately checked on screen. Working with XML, on the other hand, requires a sense of the abstract – the text flow is broken up by tags of the document structure. The layout only follows at a further stage in production. SimQin shows the document in layout mode from the outset. Additionally, however, the XML document structure and organisation are made visible.

Starting Price: Free

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Less

Less (which stands for Leaner Style Sheets) is a backwards-compatible language extension for CSS. This is the official documentation for Less, the language and Less.js, the JavaScript tool that converts your Less styles to CSS styles. Because Less looks just like CSS, learning it is a breeze. Less only makes a few convenient additions to the CSS language, which is one of the reasons it can be learned so quickly. Mixins are a way of including ("mixing in") a bunch of properties from one rule-set into another rule-set. Less gives you the ability to use nesting instead of, or in combination with cascading.

Starting Price: Free

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Markdown

Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML). Thus, “Markdown” is two things: (1) a plain text formatting syntax; and (2) a software tool, written in Perl, that converts the plain text formatting to HTML. See the Syntax page for details pertaining to Markdown’s formatting syntax. You can try it out, right now, using the online Dingus. The overriding design goal for Markdown’s formatting syntax is to make it as readable as possible. The idea is that a Markdown-formatted document should be publishable as-is, as plain text, without looking like it’s been marked up with tags or formatting instructions. While Markdown’s syntax has been influenced by several existing text-to-HTML filters, the single biggest source of inspiration for Markdown’s syntax is the format of plain text email.

Starting Price: Free

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LaTeX

LaTeX, which is pronounced «Lah-tech» or «Lay-tech» (to rhyme with «blech» or «Bertolt Brecht»), is a document preparation system for high-quality typesetting. It is most often used for medium-to-large technical or scientific documents but it can be used for almost any form of publishing. LaTeX is not a word processor! Instead, LaTeX encourages authors not to worry too much about the appearance of their documents but to concentrate on getting the right content. To produce this in most typesetting or word-processing systems, the author would have to decide what layout to use, so would select (say) 18pt Times Roman for the title, 12pt Times Italic for the name, and so on. This has two results: authors wasting their time with designs; and a lot of badly designed documents! LaTeX is based on the idea that it is better to leave document design to document designers, and to let authors get on with writing documents.

Starting Price: Free

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OCaml

OCaml is a general-purpose, industrial-strength programming language with an emphasis on expressiveness and safety. OCaml’s powerful type system means more bugs are caught at compile time, and large, complex codebases are easier to maintain. This makes it a good language for running critical code. At the same time, sophisticated inference makes the type system unobtrusive, creating a smooth developer experience. One is a bytecode compiler which generates small, portable executables and is very fast. The other is a native code compiler that produces more efficient machine code; its performance matches the highest standards of modern compilers. OCaml has great support for the most popular editors. VS Code is recommended for beginners, and for power users there is deep integration with Vim and Emacs. OCaml has a rich and dynamic community and best-in-class tooling.

Starting Price: Free

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PHPUnit

PHPUnit requires the dom and json extensions, which are normally enabled by default. PHPUnit also requires the pcre, reflection, and spl extensions. These standard extensions are enabled by default and cannot be disabled without patching PHP’s build system and/or C sources. The code coverage report feature requires the Xdebug (2.7.0 or later) and tokenizer extensions. Generating XML reports requires the xmlwriter extension. Unit Tests are primarily written as a good practice to help developers identify and fix bugs, to refactor code and to serve as documentation for a unit of software under test. To achieve these benefits, unit tests ideally should cover all the possible paths in a program. One unit test usually covers one specific path in one function or method. However a test method is not necessarily an encapsulated, independent entity. Often there are implicit dependencies between test methods, hidden in the implementation scenario of a test.

Starting Price: Free

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Jasmine

Jasmine attempts as best as possible to follow semantic versioning. This means we reserve major versions (1.0, 2.0, etc.) for breaking changes or other significant work. Most Jasmine releases end up being minor releases (2.3, 2.4, etc.). Major releases are very infrequent. Jasmine generally avoids dropping support for browser or Node versions except in major releases. The exceptions to this are Node versions that are past end of life, browsers that we can no longer install locally and/or test against in our CI builds, browsers that no longer receive security updates, and browsers that only run on operating systems that no longer receive security updates. We’ll make reasonable efforts to keep Jasmine working in those environments but won’t necessarily do a major release if they break.

Starting Price: Free

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Karma

The main goal for Karma is to bring a productive testing environment to developers. The environment being one where they don't have to set up loads of configurations, but rather a place where developers can just write the code and get instant feedback from their tests. Because getting quick feedback is what makes you productive and creative. Test your code on real browsers and real devices such as phones, tablets or on a headless PhantomJS instance. Control the whole workflow from the command line or your IDE - just save a file and Karma will run all the tests. Karma also watches all the files, specified within the configuration file, and whenever any file changes, it triggers the test run by sending a signal to the testing server to inform all of the captured browsers to run the test code again. Each browser then loads the source files inside an IFrame, executes the tests and reports the results back to the server.

Starting Price: Free

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JMockit

The toolkit is provided as a set of artifacts deployed to the Maven Central repository. It requires Java 7 or newer for test execution; tests must use JUnit or TestNG. For instructions on how to add the library to a Java project, see Running tests with JMockit. In this tutorial we examine the APIs available in the library, with the help of example tests (using Java 8). The central API - a single annotation - provides support for the automatic instantiation and initialization of the objects to be tested. Then we have the mocking API (also known as the "Expectations" API), intended for tests which use mocked dependencies. Finally, there is a small faking API (aka the "Mockups" API), which can be used for the creation and application of fake implementations that avoid the full cost of external components.

Starting Price: Free

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unittest

Python

The unittest unit testing framework was originally inspired by JUnit and has a similar flavor as major unit testing frameworks in other languages. It supports test automation, sharing of setup and shutdown code for tests, aggregation of tests into collections, and independence of the tests from the reporting framework. A test fixture represents the preparation needed to perform one or more tests, and any associated cleanup actions. This may involve, for example, creating temporary or proxy databases, directories, or starting a server process. A test suite is a collection of test cases, test suites, or both. It is used to aggregate tests that should be executed together. A test runner is a component which orchestrates the execution of tests and provides the outcome to the user. The runner may use a graphical interface, a textual interface, or return a special value to indicate the results of executing the tests.

Starting Price: Free

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xUnit.net

xUnit.net is a free, open source, community-focused unit testing tool for the .NET Framework. Written by the original inventor of NUnit v2, xUnit.net is the latest technology for unit testing C#, F#, VB.NET and other .NET languages. xUnit.net works with ReSharper, CodeRush, TestDriven.NET and Xamarin. It is part of the .NET Foundation, and operates under their code of conduct.

Starting Price: Free

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Puppeteer

Most things that you can do manually in the browser can be done using Puppeteer! Puppeteer-core is intended to be a lightweight version of Puppeteer for launching an existing browser installation or for connecting to a remote one. Be sure that the version of puppeteer-core you install is compatible with the browser you intend to connect to. Puppeteer will be familiar to people using other browser testing frameworks. You create an instance of Browser, open pages, and then manipulate them with Puppeteer's API. By default, Puppeteer downloads and uses a specific version of Chromium so its API is guaranteed to work out of the box. To use Puppeteer with a different version of Chrome or Chromium, pass in the executable's path when creating a Browser instance.

Starting Price: Free

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Playwright

Playwright supports all modern rendering engines including Chromium, WebKit, and Firefox. Test on Windows, Linux, and macOS, locally or on CI, headless or headed. Playwright waits for elements to be actionable prior to performing actions. It also has a rich set of introspection events. The combination of the two eliminates the need for artificial timeouts - the primary cause of flaky tests. Playwright assertions are created specifically for the dynamic web. Checks are automatically retried until the necessary conditions are met. Configure test retry strategy, capture execution trace, videos, screenshots to eliminate flakes. Browsers run web content belonging to different origins in different processes. Playwright is aligned with the modern browsers architecture and runs tests out-of-process. This makes Playwright free of the typical in-process test runner limitations.

Starting Price: Free

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Nightwatch.js

Nightwatch.js is an integrated, easy to use End-to-End testing solution for web applications and websites, written in Node.js. It uses the W3C WebDriver API to drive browsers and perform commands and assertions on DOM elements. Simple but powerful syntax which enables you to write tests very quickly, using Javascript (Node.js) and CSS or Xpath selectors. Typescript is supported as well. Built-in command-line test runner which runs the tests either sequentially or in parallel, with retries and implicit waits. Also supports grouping of test suites and tags. Manages automatically Selenium or WebDriver services (ChromeDriver, GeckoDriver, Edge, Safari) in a separate child process. Fluent and easy to work with Page Object Model support to better organise elements and sections, with support for both CSS or Xpath selectors.

Starting Price: Free

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Marionette

Organize your app in terms of small Views. Marionette makes it easy to compose rich layouts out of small components. We've added tons of features from templateHelpers, to a declarative UI hash, that will keep you from ever wanting to go back. Share complex UI interactions across views. Behaviors are like mixins, without all of the pain associated with property collision. Decoupled communication between your application components with a powerful messaging system. Write classes with the same API as your views. Marionette Objects support features like extend, events, initialize, and more. Marionette community is home to the most welcoming and vibrant discussions in the Backbone ecosystem. Stop spending more time thinking about your framework than your app. Marionette will never get in the way of you and your code.

Starting Price: Free

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Mockito

Mockito is a mocking framework that tastes really good. It lets you write beautiful tests with a clean & simple API. Mockito doesn’t give you hangover because the tests are very readable and they produce clean verification errors. Read more about features & motivations. Top 10 Java library across all libraries, not only the testing tools. In late 2013 there was an analysis made of 30.000 GitHub projects. Although Mockito reached number 9 in the main report, mockito-core and mockito-all are the same tool and therefore the factual position of Mockito is number 4, surpassing famous tools like Guava or Spring. Treat this study as an indicator of a big impact that Mockito makes every day on unit tests written in Java.

Starting Price: Free

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PowerMock

Writing unit tests can be hard and sometimes good design has to be sacrificed for the sole purpose of testability. Often testability corresponds to good design, but this is not always the case. For example final classes and methods cannot be used, private methods sometimes need to be protected or unnecessarily moved to a collaborator, static methods should be avoided completely and so on simply because of the limitations of existing frameworks. PowerMock is a framework that extends other mock libraries such as EasyMock with more powerful capabilities. PowerMock uses a custom classloader and bytecode manipulation to enable mocking of static methods, constructors, final classes and methods, private methods, removal of static initializers and more. By using a custom classloader no changes need to be done to the IDE or continuous integration servers which simplifies adoption.

Starting Price: Free

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MockK

Mocking is a technique to make testing code readable and maintainable. In three consequent articles, I would like to show the basics, features, and quirks of the MockK library. It is a new open-source library (github repository) focused on making mocking in Kotlin great. Injection first tries to match properties by name, then by class or superclass. Check the lookupType parameter for customization. Properties are injected even if private is applied. Constructors for injection are selected from the biggest number of arguments to lowest.

Starting Price: Free

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OpenTest

OpenTest is a free and open source functional test automation framework for web applications, mobile apps and APIs, built for scalability and extensibility, with a focus on enabling the mainstream test automation practices. OpenTest is a feature-reach tool that requires little to no coding skills and can handle virtually any type of functional test automation project. Keywords are high-level building blocks which hide the complexity of the underlying technology and let you build concise, readable and maintainable tests. No coding skills required.Run multiple test sessions in parallel, limited only by the available hardware resources. When you've maxed out your local machine(s), spin up more test actors in the cloud(s). JavaScript code can be embedded organically anywhere within your keyword-driven test to cover complex test scenarios. Run a test multiple times, over a set of data records maintained in a separate data file.

Starting Price: Free

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Robot Framework

Robot Framework is a generic open-source automation framework. It can be used for test automation and robotic process automation (RPA). Robot Framework is supported by Robot Framework Foundation. Many industry-leading companies use the tool in their software development. Robot Framework is open and extensible. Robot Framework can be integrated with virtually any other tool to create powerful and flexible automation solutions. Robot Framework is free to use without licensing costs. Robot Framework has an easy syntax, utilizing human-readable keywords. Its capabilities can be extended by libraries implemented with Python, Java or many other programming languages. Robot Framework has a rich ecosystem around it, consisting of libraries and tools that are developed as separate projects.

Starting Price: Free

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Best Free Application Development Software - Page 36

Compare the Top Free Application Development Software as of November 2026 - Page 36