MLton is a whole-program optimizing Standard ML compiler. It generates standalone executables with excellent runtime performance, supports the full SML 97 language, and has a complete basis library. It also has a fast C FFI, source-level time and allocation profiling, and many useful libraries.
mod_backhand is a load balancing module for Apache. It provides per-request HTTP redirection within a heterogeneous Apache server cluster. Each request is processed and run through a set of "candidacy functions" to determine which server is best suited to respond. The request is then proxied to that server. Facilities are in place to allow you to write your own dynamically loadable decision making algorithms. Everything about the request and the current availability of resources can be used in the decision-making process.
The SeaMonkey project is a community effort to develop an all-in-one Internet application suite. It contains an Internet browser, email and newsgroup client with an included Web feed reader, HTML editor, IRC chat, and Web development tools, and is sure to appeal to advanced users, Web developers, and corporate users. It uses much of the Mozilla source code powering such successful siblings as Firefox, Thunderbird, Camino, Sunbird, and Miro.
MPlayer is a movie and animation player that supports a wide range of codecs and file formats, including MPEG 1/2/4, DivX 3/4/5, Windows Media 7/8/9, RealAudio/Video up to 9, Quicktime 5/6, and Vivo 1/2. It has many MMX/SSE(2)/3Dnow(Ex) optimized native audio and video codecs, but allows using XAnim's and RealPlayer's binary codec plugins, and Win32 codec DLLs. It has basic VCD/DVD playback functionality, including DVD subtitles, but supports many text-based subtitle formats too. For video output, nearly every existing interface is supported. It's also able to convert any supported files to raw/divx/mpeg4 AVI (pcm/mp3 audio), and even video grabbing from V4L devices.
Mup produces very high quality PostScript printed music or a MIDI file from a text input file. It can handle almost any kind of music, instrumental or vocal, including tablature, shaped notes, guitar grids, alternate tunings, user-defined symbols, and much more. Mup has been under active development since 1992.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.