There is prototype implementation of GUI, however I do not have time to finish it. It is in PyGTK, uses XML-RPC to communicate with RTS2. XML-RPC interface is described here. Code is at SVN http://rts-2.svn.sf.net/viewsvn/rts-2/trunk/pyrts2, to get it and run it execute:

user@host:~$ svn co https://svn.code.sf.net/p/rts-2/code/trunk/pyrts2
user@host:~$ cd pyrts2
user@host:~/pyrts2$ ./pyrts2.py

You will need python-gtk2 installed:

user@host:~$ sudo apt-get install python-gtk2

And you need to have rts2-xmlrpcd running. Currently, GUI support scheduling and have a tool to display schedule. There is a screen shot: