Geany is a lightweight and powerful programmer's text editor that runs on Linux, Windows, and macOS. It's designed to be a flexible and feature-rich IDE/editor that doesn't bog down the user's workflow. Here's a summary of its functionalities:

• Cross-Platform: Geany operates on Linux, Windows, and macOS.

• Multi-language support: It has built-in support for over 50 programming languages. Some popular languages supported are C, Java, PHP, HTML, JavaScript, Python and Perl. It also supports other filetypes like ini-style config files and SQL files.

• Customizable: Geany is heavily customizable, with options for color themes and adding new filetypes. Many settings are available to adjust it to individual preferences.

• Plugin System: Geany has a plugin system that allows users to add more features to the editor, and developers can create new features and improve existing ones. Some available plugins are VCS (Git, SVN), SpellCheck, Project Organizer and Translation Helper.

• Community-Driven: Geany is free software under the GPL v2 license, allowing customization and community contributions. It has an active community of both professionals and hobbyists who contribute improvements across platforms.

• Fast and Small: The software is designed to be a lightweight IDE/editor.

Geany aims to be a good GUI, cross-platform, powerful IDE/editor.