Brian, I'm trying to use Foolscap as a component in a system where it has to work with a lot of data that gets passed back from XML-RPC services. So far it's been a pleasant experience: it's much more accessible than 'oldpb', the intro was easy to read and follow, and it looks and feels well-written: thank you! XML-RPC was chosen in the interests of 'extreme interoperability', but there are small parts of the system where the data rate is somewhat too great: for these, XML-RPC is utterly unsuited, but Foolscap seems to be a good choice. As a side-effect of this XML-RPC dependency, I needed to be able to pass xmlrpclib.DateTime objects over PB. The documentation states the following: "Note that you can also register an ICopyable adapter on third-party classes to avoid subclassing." I spent a while trying to get this working by writing adapation classes and whatnot. I got the send part working but couldn't convince the receiver to recognise and deserialise the class. Then I looked through the source and test code and realised that you've provided an easier interface to do it, but haven't mentioned this in the documentation. Given that being able to send third-party classes over Foolscap is probably a very common requirement, I thought I'd send a simple example for others in the same position lest they be led into thinking that this requires subclassing or writing adaptation classes. You could even insert these in the part of the documenation about copyables where it says "TODO: example" :-) Regards, Ricky