Rapid applications development tool and libraries for FPC
The Lazarus IDE is a stable and feature rich visual programming environment for the FreePascal Compiler. It supports the creation of self-standing graphical and console applications and runs on Linux, FreeBSD, MacOSX and Windows.
A free IDE for C#, VB.NET, & Boo projects on Microsoft's .NET platform
SharpDevelop is the open-source IDE for the .NET platform. Write applications in languages including C#, VB.NET, F#, IronPython and IronRuby, as well as target rich and reach: Windows Forms or WPF, as well as ASP.NET MVC and WCF. It starts from USB drives, supports read-only projects, comes with integrated unit and performance testing tools, Git, NuGet and a lot more features that make you productive as a developer.
Denwer is a collection of often-used web-servers for web-programmers. It is used to debug web-sites under Win32. Denwer includes: friendly installer; Apache; PHP; MySQL; Perl; virtual host management system; phpMyAdmin; sendmail stub; start/stop manager.
Reverse engeneering tool, useful to translate compiled object files or raw binary files, created with C-style languages back to C. Second purpose is to detect possible bugs or trojans (255b is too small to describe these methods)