Opera RSS to OPML
Soup is beautiful
Using Leo with reST
Jython is great
Quick UI for DocIndexer
The System Modeling Workbench is a collection of tools for editing, storing, analyzing and verifying models. It is based on the OMG MOF and UML standards and it is implemented using the Python programming language.
I need to try this one out and compare it with ArgoUML.
Personally, I think there is no free or commercial CASE tool available now that can come anywhere near Oracle Designer.
While thinking about Python, there is a good tutorial on IBM dW about XML-RPC.