php implementation of SQLite like functionality

I am currently developping my own CMS using PHP/SQL on the server side and Javascript on the client side. A previous version of it was pure Javascript but I realised that this was making my website unaccessible to no-script users.

I therefore shifted my paradigm to a server building a basic version and javascript providing eyecandy options.

The data are in a SQL database accessed using PDO.

Some co-workers wanted to use my CMS but they are not used to MySQL and dont like to have to migrate their databases when migrating their website (which, for many reasons, can happen quite often).

I thought of using SQLite as the database would be a simple file that could be moved easiely. However SQLite is not available in our institution professional web pages service.

I understand that using a php based impementation would limit the capabilities of load balancing (which you have when physically separating the webserver and the database) but my database would stay very small and shouldn't cause performances issues.

Question:

• Is there any php impementation of SQLite that would work even when sqlite and pdsqlite modules are not available ?
• Is there any other solution to have PDO fallback to a basic file-based database that could be migrated easielly ?