Free lightweight software for linux

Lightweight C++ is a programming language that looks like C++ (a lightweight C++ dialect) and is directly translated to readable C by the lwc preprocessor.
Its more "K&R" and, well, more lightweight. Important thing about lightweight C++ is that by studying the generated C code it is easy to understand how OOP features are implemented and what is the cost of everything.
Adding new features and extensions is also very easy (much easier than adding new C++ extensions to gcc at least), and this is one of lwc goals: To keep evolving.
Main features:
- function overloading,
- member functions,
- inheritance,
- virtual functions (polymorphism),
- multiple inheritance,
- virtual inheritance and pure virtual functions,
- constructors, destructors,
- new and delete,
- default function arguments,
- simple exceptions (no auto destruction of locals)
- and a mechanism of simplistic templates (implemented as high-level multi-line macros).
- operator overloading (works with ptrs when it can)
- +other
Enhancements:
- Changed the generated code for the gcc cleanup attribute so that if a constructor throws, the destructor is not invoked. As in the simple case where we dont have the cleanup attribute and like C++.

ePDFView is a lightweight PDF Viewer. ePDFView uses GTK+, Poppler and cairo libraries.
Main features:
- Support for encrypted files.
- Document index viewer.
Although its under continuous development.

LightWeight Time Tracker (LWTT) is a very simple time-tracking program. LightWeight Time Tracker provides independent real-time tracking of multiple tasks (such as programming, lectures, presentations, etc.).

The data are saved to an XML file under the home directory.

ltpanel is a lightweight window list for the X Window System, similar to GNOMEs window list applet.

It has been tested on IceWM and should work with any GNOME-compliant window manager. It is based on Peter Zeleznys fspanel.

JavaAmp is a clone of the well known multimedia player WinAmp.

JavaAmp player uses the Lightweight Java Game Library (LWJGL) and FMOD for playing music and visualizing it.

Enter aims at beign lightweight, yet highly configurable login manager for X. Supporting many different desktop setups. It is written in C with minimal dependencies, making it an excellent choice when using other lightweight window managers, such as fluxbox.