aphasia is an advanced scripting language for the web. It features a type-safe core, C++ modules with signatures, an optimizing "compiler", higher-order functions, built-in database support, garbage collection, and more.
From the XML definition of your database, DewDrop will generate clean and human-readable SQL DDL code for any supported target database. This means you can define your database just once in XML, and have it work for any database automatically.
This project is a lightweight server written in Ocaml for highly interactive webpages or even online browser based games. The server can already be used as a fast frontend to a MySQL database. The software should work on *nix and windows.
XMLbase is a new specification/engine for writing databases in pure XML. It is currently incomplete, and is in need of developers. Its key advantage is that you could share database files between applications, and even distribute them over the internet.