jUDO (java Universal Data Objects) handles coding against a database Independent of database (plugins for db2/Oracle/Cloudscape/mysql/mysql etc).The code is generated "runtime" , just give the method names and jUDO derives the code/sql.
The iChilli mobile J2EE platform provides a J2EE compliant runtime environment for both server and mobile platforms, such as J2ME, MIDP or other CLDC based devices. For example iChilli runs on the PersonalJava enabled Sharp Zaurus and Compaq's iPAQ.
[PROJECT ABANDONED] This project will provide a 100% pure Java database implementation accessible via JDBC. The database is stored in plaintext files and loaded into RAM at runtime. Implements mySQL datatypes for trivial migration to/from mySQL.