Off-line content management en search application for knowledge base

Hello,

I'm looking for a CM/search-solution which can be used on a laptop,
both with and without an internet connection.

For example: employees must lookup (browse, navigate, search) through
a lot of documents (PDF, Word, Excel, company databases), in order
to find the information they need. They don't have a (secure)
internet connection in most cases, so they must work off-line.

These employees are online from time to time, and then can synchronize/
replicate their database with the central database. Search indexes
can be updated on the laptop. This way they will get access to the
latest/newest documents and the findings of their colleagues.

Wireless connections (wifi, gprs, etc.) are not possible in this
situation.

The only options I currently see, are custom applications, based
on Lotus Notes, Python/Zope/Plone, .NET/C# and maybe something like
a local search tool such as dtSearch.

Does anybody know some Content Management Frameworks or other
applications that are appropriate in this situation? (so have support
for synchronize/replication, local search engine, etc.)

Any input would be appreciated,
Regards,

Pieter