SQLite is fine as a single-access database, but it gets risky when used by more than one user at a time. MySQL, Firebird, PostgreSQL etc. are more difficult to deploy and are simply overkill for my use.
Ideally, I'd like a compact, single-EXE server meant to run on low-spec hardware (eg. 128MB RAM, 256MB flash RAM) that would be as easy to work with as SQLite, and is available for Linux (and Windows, so I can use the same code client-side in case customers prefer a regular PC.)
Do you know of an application that fits those requirements?
Give Firebird a try. It's cross platform and lightweight. Databases consist of single files.
Try H2,Its a Java based SQL database engine.....
- Very fast, open source, JDBC API
- Embedded and server modes; in-memory databases
- Browser based Console application
- Small footprint: around 1.5 MB jar file size
You might try looking at Apache Derby (http://db.apache.org/derby/). It's Java, so it'll be portable and it's definitely lightweight.
Another option is HSQLDB. It's light, fully Java and multithread. I used in personal projects with very good results.