Sorry for any misunderstanding, some comments below would be better if explained since 1st post :

a) my suggestion "Try again later" was supposed to mean "try to install using 'apt-get install' later", as this is documented in the 1st post;

b) PyGlet is a Python module to be used by other softwares, so it has no icon and doesn't appear in application manager (because it doesn't use a "user" section);

c) PyGlet depends on Mesa dependencies which are not optified and are in extras-testing repositories;

d) only some examples (and features) of PyGlet (for desktop) work on Maemo 5 OS;

e) due to (c) and (d), PyGlet probably won't be promoted to extras repository, but it is up to you user decide;

f) SymPy Interactive Shell (python-sympy-ui), if listed PyGlet as a dependency (to automatically install SymPy, IPython, PyGlet and Mesa dependencies) would give the (c)-(d) problems to all SymPy users : SymPy Interactive Shell would be limited to extras-testing, 6.4 MB of root space would be used, etc;

g) so, PyGlet is an optional dependence of SymPy (as it is in any desktop OS) and PyGlet installation is manual. If PyGlet and its Mesa dependencies were 100% ok (in extras repository), I could include PyGlet as a dependency of SymPy Interactive Shell so everything would be easily installed;

Think of PyGlet (partially) running in Maemo 5 OS as a gift, an exception because no other mobile OS has PyGlet working.