Codeit

Geany is a powerful, stable and lightweight programmer's text editor that provides tons of useful features without bogging down your workflow. It runs on Linux, Windows and MacOS is translated into over 40 languages, and has built-in support for more than 50 programming languages. One the primary reasons for Geany's existence is that there is a need for a decent, GUI, lightweight, cross-platform, flexible and powerful IDE/editor. Many editors meet one or more of these requirements but fall short on others. Using the GPL v2 license, Geany assures that not only can you customize and hack it, but that everyone benefits from changes the community makes. Many parts of Geany are heavily customizable like color themes (Geany Themes) or adding new filetypes. Furthermore, Geany provides many settings to let you adjust it to your needs and preferences. Many supported filetypes including popular programming languages like C, Java, PHP, HTML, JavaScript, etc.

CotEditor is exactly made for macOS. It looks and behaves just as macOS applications should. CotEditor launches so quick that you can write your text immediately when you want to. CotEditor is developed as an open-source project that allows anyone to contribute. Colorize more than 50 pre-installed major languages like HTML, PHP, Python, Ruby or Markdown. You can also create your own settings. Split a window into multiple panes to see different parts of your document at the same time. Inspect Unicode character data of each selected character in your document and display them in a popover. There are no complex configuration files that require geek knowledge. You can access all your settings including syntax definitions and themes from a standard preferences window. You don't need to lose your unsaved data anymore. CotEditor backups your documents automatically while editing. Check and list-up the characters in your document that cannot convert into the desired encoding.