Krita

Krita is a FREE and open source painting tool designed for concept artists, illustrators, matte and texture artists, and the VFX industry. Krita has been in development for over 10 years and has had a...
Language(s): C++, Qt
Operating system(s): Unix, Linux, Windows, Mac OS
License: GPLv2 or later.

LAMMPS

LAMMPS is a classical molecular dynamics code, and an acronym for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has potentials for solid-state materials (metals, semiconductors)...
Language(s): C++
Operating system(s): Linux, Mac OS X, Windows
License: GNU General Public License

LedgerSMB

The LedgerSMB project brings accounting software integrating invoicing, order processing, quotations and more (ERP) to small and midsize businesses. Features include: Sales (Invoices, Orders, Q...
Language(s): Perl, PL/pgSQL
Operating system(s): Unix, Linux, Mac OS, Windows, Android
License: GPLv2 General Public License Version 2

LiVES

LiVES mixes realtime video performance and non-linear editing in one professional quality application. It will let you start editing and making video right away, without having to worry about formats,...
Language(s): C, Perl, Python
Operating system(s): Linux, Unix
License: GNU General Public License version 3 or higher.

LibreCAD

LibreCAD (originally CADuntu) is a free and open-source 2D CAD application, which uses Qt (a cross-platform application framework). The project started around 2010 as a fork of QCAD 2.0.5.0....
Language(s): C++
Operating system(s): Windows, Mac OS, Unix, Linux
License: GNU General Public License