JWM

JWM (also known as Joe's Window Manager) is an open source, highly customizable, free and lightweight window manager implemented in C and designed especially for the X Window System, supporting all POSIX-compliant operating systems, including GNU/Linux.

It’s heavily used on several lightweight distributions of Linux

Damn Small Linux and Puppy Linux were among the first GNU/Linux distributions that were built around the JWM window manager from the ground up. Today, Joe's Window Manager can be found in many Linux kernel-based operating systems and it is considered a good alternative to clunky graphical desktop environments.

The software is written in the C programming language and uses only the Xlib library, in order to provide a small footprint and a good window manager for less powerful systems (e.g. Raspberry Pi) or computers with old or semi-old hardware components. JWM is extremely fast, versatile and low on resources, providing users with a traditional look and feel, similar to the one of Windows XP.

A flexible and extendable window manager

Joe's Window Manager can be easily extended through extensions, which in turn require the presence of various libraries. For example, it requires the libXext library for the shape extension, the libXmu library for the shape extension and to draw rounded windows, as well as the libXext library for the render extension.

Additionally, the libjpeg library can be used for supporting JPEG icons and backgrounds, the libXpm library for supporting XPM icons and backgrounds, the Cairo and libRSVG libraries for supporting SVG icons and backgrounds, the libpng library for supporting PNG icons and backgrounds.

Last but not least, the libXinerama library can be used for supporting multi-monitor setups (Xinerama), support for TrueType and antialiased fonts is provided by the libxft library, and support for right-to-left languages is powered by the libfribidi library.