I seem to be getting this question every two weeks or so, so I thought I'd answer it here.
Yes, the code is still being maintained. There just hasn't been any need to update it lately.
See ... when OpenSRS updates their perl client, it's usually because they've added a new command to the API or changed the templates. Since the PHP client doesn't include templates, and since I removed the client-side check for a valid command, all of those updates are not needed for the PHP client.
That said, if any problems do crop up with your install, be sure to send your questions to firstname.lastname@example.org.