Hi,
I am working on a pure-PHP VOSpace 1.1 endpoint in front of iRODS. The code is part of the shared Google Code project that Norman Gray set up. Right now, I'm only targeting a minimal set of features, namely public, read-only access into an iRODS collection. The code has not gotten very far yet, but I'm up the learning curve on using PHP's native SOAP classes. Also, as I'm building this I will try to abstract it enough so that adding support for other backends (such as a simple file store) is possible.
I've gone with PHP to take advantage of Sifang Lu's iRODS client that's written in pure PHP. As you can imagine, this make deploying the server much easier. Also, Sifang and I are on the same campus, and he's been very accessible.
Guy Rixon suggested that I share this on the mailing list, since there are likely other groups working on a similar project. If anyone is interested in collaborating, please let me know.
--Rick
Google Code project page
http://code.google.com/p/volute/
PHP Endpoint
http://tinyurl.com/2u33pw