(.dot source)
Asterix is a BNF-like, low- to medium-level programming language that has been bootstrapped using prox2, and is based on the experience gained from building prox2 and its predecessors (which are described briefly below, and in a bit more detail on the compiler project page).
Aximgview is an image viewing program, somewhat similar to xloadimage, written in Asterix. It does not use Xlib (the library normally used to write X11 client programs) and instead implements the necessary parts of the X11 network protocol directly.
This is a series of decreasingly unsophisticated compilers, bootstrapped from just a hexadecimal-to-binary converter.
Most of them are obsolete and maintained only as necessary to boostrap Asterix. The metacompilers in this series take significant inspiration from META II. Those who find META II itself particularly interesting may want to have a look at the mcss (metacompiler stepping stones) repository. Although there isn't much documentation, it does include (as an example and test case) compilers for both META II’s source and target language, allowing them to be translated to native machine code.
See the (meta-)compiler project page for more detailed descriptions and download links.