The mother modular generic compiler is designed to compile arbitrary computer languages to arbitrary assembler code. the desired language and assembler is specified as tables, so there is no need to generate something like a "cross compiler". Further, mother is modular, as it is made up of a set of separate tools which are used in the very Unix fashion of calling them in a pipe.
Motor is a text-mode integrated programming environment for Linux. It consists of an editor with syntax highlighting, a project manager, a makefile generator, gcc, ctags, gdb, autoconf/automake and grep front-ends. CVS integration is also provided. It allows one to edit, compile, and debug programs without a need to leave the IDE, automatically check in/out files from a CVS repository and import projects into CVS, and generate distribution packages (tar.gz and RPM). The color schemes are customisable.
nwcc is a C compiler for Unix systems. It targets Linux, Mac OS X, BSD, and Solaris on 80x86 (with nasm and gas), Linux, Mac OS X, and FreeBSD on AMD64 (with yasm and gas), Solaris and Linux on SPARC (64-bit), AIX and Linux on PowerPC (32- and 64-bit), and IRIX on MIPS (64-bit). Cross-compilation is also supported. It doesn't feature any software development support beyond plain compilation.
nyu is a combination of modern academic approaches to parsing formal grammars from PEGs and expression grammars that represents the new state of the art in parser generators. nyu grammars are written in a powerful language based on PEGs (parsing expression grammars) but with modifications to allow both the AST and the parser to be specified intuitively in a single grammar. nyu outputs parsers that take advantage of the chilon::parser meta-programming library for C++. The generated parsers are almost as concise and readable as the input grammars, yet perform as well as hand-written C code. nyu ASTs are built using tuples, variant types, and lists, and allow self referential parsers and AST nodes to be manipulated. Advanced features such as hashed containers and grammar inheritance are also possible and well tested. nyu is currently powerful enough to deal with complex grammars and bootstraps its own parser.
Oberon2 is a simple and safe object-oriented language created by N.Wirth, the author of Pascal and Modula2. It is statically strongly typed and has garbage collection. Most of good ideas incorporated in design of Java were in Oberon2 long before. OOC is an open source project to produce a family of optimizing Oberon2 compilers. The compiler with an ANSI C back-end, oo2c, is quite mature, and provides a complete and convenient Oberon2 development environment. It comes with a rather comprehensive standard library, Code Navigator, and an Emacs mode. It is easy to call C functions and libraries from Oberon2.
phc is a compiler for PHP with support for plugins. Programmers can use it to compile PHP source into an executable program, compile a Web application into a Zend PHP extension, pretty-print PHP code, or combine many PHP scripts into a single file (experimental). Tool developers can use phc to analyze, modify, or refactor PHP scripts using C++ plugins, or convert PHP into a well-defined XML format, process it with your own tools, and convert it back to PHP.