DOxygen

Generate documentation from source code

Tool for generating documentation from annotated C++ sources, but it also supports other popular programming languages such as C, Objective-C, C#, PHP, Java, Python, IDL (Corba and Microsoft flavors), Fortran, VHDL, Tcl, and to some extent D.

DotGNU Portable.NET

An Open Source Compiler

Intended as a replacement for Microsoft's .Net, DotGNU provides a variety of tools to compile and run applications. The goal of DotGNU Portable.NET is to build a suite of Free Software tools to compile and execute applications for the Common Language Infrastructure (CLI), which is often referred to as ".NET".
It currently supports C and C#.

ISPCP

ispCP (Internet Service Provider Control Panel) is an open source project founded to build a Multi Server Control and Administration Panel. This Control Panel is usable by any Internet Service Provider (ISP).

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ISPConfig for Linux

Open source hosting control panel

ISPConfig is an open source hosting control panel for Linux, licensed under BSD license. ISPConfig allows administrators to manage websites, e-mail addresses and DNS records through a web-based interface. The software has 4 login levels: administrator, reseller, client and email-user.