InvocationTesting is a project mainly written in OBJECTIVE-C and C, it's free.
Objective-C Method forwarding fun (not that it will be fast)
Tries out a way that, when an object holds an internal NSDictionary, it hosts Objective-C properties that are specified as @dynamic, and those properties will be resolved at run time.
The fun part is in IRDynamicPropertiesObject, and is coded against http://stackoverflow.com/questions/4574465/objective-c-respondstoselector-question .
The code is actually under the New BSD license, e.g. do whatever you would like to do with it, as it is wished to be useful.