Mac OS X Softwares to Cross-platform

Tcl (Tool Command Language) is a dynamic, high-level scripting language ideal for rapid application development, scripting, and automation, particularly strong in graphical user interfaces.

Aquamacs Emacs is a robust, free, and open-source text editor specifically tailored for the macOS environment, built upon the powerful Emacs framework. It provides a familiar Mac experience while leveraging Emacs' extensive customization and feature set, making it ideal for developers across various programming languages.

JOE (Joe's Own Editor) is a venerable, full-featured terminal-based text editor known for its ease of use and extensive feature set, making it suitable for both casual editing and complex programming tasks within the command line environment.

wxMEdit is a versatile cross-platform text and hex editor, serving as a powerful alternative to the discontinued MadEdit. Built on C++ and wxWidgets, it provides developers and advanced users with robust features for editing text files and binary data.

Jython is a Python implementation designed to run on the Java Virtual Machine (JVM). It allows Python developers to leverage Java libraries and frameworks, and Java developers to integrate Python scripting into their applications, bridging the gap between the two ecosystems.

Tomato is a highly regarded custom firmware designed for Broadcom-based routers, offering advanced features and enhanced control beyond the stock manufacturer firmware. While discontinued, it remains a popular choice for users seeking improved network performance, diagnostics, and configuration options on compatible hardware.

SunVox is a compact yet powerful modular synthesizer and tracker-based music production environment for creating electronic music on various platforms.

OpenFrameworks is a free and open-source C++ toolkit crafted for creative coding. It provides a powerful yet accessible environment for developing cross-platform applications focused on graphics, audio, and real-time interaction, making it ideal for artists, designers, educators, and researchers.

Chrome Secure Shell is a robust, xterm-compatible terminal emulator and native SSH client for Chrome. It provides secure remote access to servers directly from your browser, offering essential features for network administration and development tasks within the familiar Chrome environment.

JRuby is a robust implementation of the Ruby programming language built on the Java Virtual Machine (JVM). It provides seamless interoperability between Ruby and Java, allowing developers to leverage the strengths of both ecosystems.

Cocos2d-x is a renowned open-source, cross-platform 2D game engine. Favored by mobile game developers for its efficiency and ease of use, it provides a robust framework for creating engaging 2D games with excellent performance across multiple devices and operating systems. Its flexibility and extensive feature set cater to both beginners and experienced developers.

Ionic Framework is an open-source UI toolkit for building high-quality, cross-platform mobile, desktop, and web applications from a single codebase. leveraging web technologies.

Pure Data (Pd) is a widely-used graphical programming environment developed by Miller Puckette. It provides a visual interface for creating interactive computer music, multimedia works, and various forms of digital art through signal processing and event modeling.

Urho3D is a free, cross-platform 2D/3D game engine written in C++ and released under the MIT license. It is known for its lightweight design and efficiency, making it a suitable choice for various game development projects.

Clojure is a dynamic, functional dialect of the Lisp programming language on the Java virtual machine (JVM). It emphasizes immutability and persistent data structures for robust concurrent programming.

DataGrip is a powerful, cross-platform IDE designed for database administrators and developers, providing a unified environment for managing multiple databases with intelligent coding assistance, schema navigation, and integrated tools.

Free Pascal Compiler (FPC) is a robust and versatile compiler for Pascal and Object Pascal, distributed under the GNU GPL. It supports numerous platforms and architectures, enabling developers to create a wide range of applications from console tools to cross-platform GUI applications.

UFRaw (Unidentified Flying Raw) is a powerful and flexible open-source application designed for processing and manipulating raw image files from digital cameras. It provides a comprehensive suite of tools for non-destructive editing, batch processing, and conversion.

Swift is a powerful and intuitive compiled programming language from Apple, building on the best of C and Objective-C without the constraints of C compatibility. It's designed for safety, performance, and modern software design patterns, enabling developers to create apps for iOS, macOS, watchOS, tvOS, and beyond.

Simple DirectMedia Layer (SDL) is a cross-platform, open-source development library offering low-level access to essential hardware like audio, input devices, and graphics APIs (OpenGL, Direct3D). It's a fundamental layer for game development and creating interactive applications.

Erlang is a powerful functional programming language designed for building highly available, scalable, and fault-tolerant soft real-time systems. It excels in concurrent and distributed environments, making it ideal for applications requiring continuous uptime and handling vast amounts of concurrent requests.

AdiIRC is a feature-rich and highly customizable free IRC client designed for both casual users and power users. It offers a portable experience, extensive customization options, and support for various IRC networks and protocols.

YACReader is a comprehensive and user-friendly comic book and manga reader and manager for various platforms. It supports popular comic file formats like CBR, CBZ, ZIP, and RAR, offering a seamless reading experience and robust library organization tools.

SoapUI is a powerful, open-source testing tool specifically designed for testing web services built on SOAP and REST architectures. It provides a comprehensive suite of features for functional, performance, and security testing.

Spek is a lightweight, cross-platform acoustic spectrogram viewer primarily designed for audio analysis. It visually represents the frequency spectrum of audio files over time, providing insights into audio quality, artifacts, and mastering issues. Ideal for audiophiles and audio engineers looking for a simple yet effective tool.

Sauce Labs offers a leading cloud-based platform for automated testing of web and mobile applications. It empowers developers and QA teams to accelerate software delivery by running tests across thousands of browser, OS, and device combinations.

Mylio helps you organize, protect, and access your photos and videos across all your devices without relying solely on cloud storage. It leverages a unique approach to keep your entire library synchronized and accessible, offering powerful organization, editing, and sharing tools.

MilkyTracker is a free, cross-platform music tracker inspired by FastTracker 2, designed for composing music in MOD and XM module formats. It's a powerful tool for creating chiptune, demoscene, and electronic music, offering precise control over sound and sequencing.

Textadept is a powerful, free, and open-source text editor designed for programmers. Focusing on speed and extensibility, it offers a minimalist interface while providing robust features like syntax highlighting, code formatting, and a built-in terminal, all heavily customizable through Lua scripting.

GTK (formerly GTK+), or the GIMP Toolkit, is a free and open-source cross-platform widget toolkit for creating graphical user interfaces (GUIs). It's written in C and offers bindings for numerous other programming languages, making it highly versatile for building desktop applications.