Patent Liability Insurance

[Bruce Alspaugh]

One of the risks we see in creating an open-source project is the 
possibility of being sued for inadvertently reinventing someone else's 
patented idea.  Basic due diligence may be enough to avoid a copyright 
infringement, but we aren't sure if that is the case for patents.  
Patent searches could prove too expensive for many open-source 
projects.  The cost of defending a patent infringement suit could put 
many open-source projects out of existence.  Are there inexpensive ways 
open-source projects can mitigate the risk of inadvertently infringing a 
third-party patent? 

I understand that is possible to purchase patent liability insurance.  
How much does patent liability insurance typically cost?  How do most 
open-source projects raise the revenue to pay for this insurance?  Do 
any of the many foundations that assist open-source projects (Apache, 
Mozilla, Eclipse, FSF, etc.) offer this insurance for the projects they 
host?

Most open-source licenses I have seen disclaim any warranty of patent 
non-infringement and therefore shift the legal risk onto the users.  Are 
the users of open source software therefore expected to purchase patent 
liability insurance?

Bruce Alspaugh