I've been using Pyo for creating synthesized musical instruments and communicating data via Open Sound Control. Also, I'm working on a personal project wich includes a bunch of light sensors and requires many attempts of mapping strategies. When looking for OSC connectors/mappers GUIs I've found just a few interesting solutions, which are usually limited to a specific OS and are available under non-free licenses.
Last month I was introduced to libmapper, "an open-source, cross-platform software library for declaring data signals on a shared network and enabling arbitrary connections to be made between them[...]". It provides python binds and works nicely together with Pyo. Libmapper developers provide a fonctional GUI for MacOS. There's out there webmapper, a web interface for libmapper, and umapper,"an Ugly TUI to libmapper".
I'm unable to use the "official" MapperGUI because I don't use Mac. Webmapper does the job, it has a really fancy interface and looks very promising, but I'm not a web person, mainly when it involves audio (it's a totally personal issue). Umapper is limited to the basic mapper functions and it's not working with recent libmapper API changes. So, I'd have a good reason to start coding a libmapper GUI myself :) Well, actually the real reason is that I wanted to know how libmapper works internally and I'm currently interested on learning a little of programming in WX, so I've just started coding pymapper, a libmapper GUI written in wxpython. It's in a very early stage but it works as it should in my GNU/Linux system. Hopefully it goes to Debian as soon as #737238 is closed.
Here's some screenshots from the GUIs mentioned above, including pymapper: