I'm working with a team that will be developing open source applications for
governments and we are doing research into a good tool set.  eXo is one of
the products we're considering using.

I thought I could get some help and advice here as to how appropriate this
product would be for us.   So far, we have the following criteria that
need to be met (in addition to the obvious ones, such as 100% open source
tools, if possible, and that they support Java apps):

 - Good for both medium-sized and larger projects (we may use a tool like
   Zope for the small projects).

 - Supports developing of well-structured, high quality systems.

 - Flexible - Gets along well with other tools and allows "plugging in"
   tools that aren't part of the platform.

 - Well established - Is used a lot, or is very likely to be used a lot,
   in the future - for both OS and commercial projects.  [Being used
    a lot implies a reputation for quality and reliability, and also tends
    to look good on the resume :-)]

Any advice, information, caveats, etc. with respect to using eXo to help
meet our criteria would be greatly appreciated.

Thanks!