Contributor License Agreements

[Bruce Alspaugh]

My company is considering releasing a software library under an 
open-source license.  We are contemplating requiring contributors to 
return a signed Contributor License Agreement similar to the one used by 
Sun[1], Apache[2], and many others.

The advantages we see with CLAs are to preserve the option of 
re-releasing under a different license, and to strengthen our ability to 
defend license violations if necessary.  The disadvantages we see are 
the added administrative burden of maintaining them, and reluctance on 
the part of contributors to sign them.

When are CLAs advisable for open source projects? Are there other CLA 
templates we should consider?

Sincerely,

Bruce Alspaugh, CTO
CompuLink, Ltd.
409 Vandiver Drive #4-200
Columbia, MO 65202-2213

[1] http://www.netbeans.org/about/legal/ca.html
[2] http://www.apache.org/licenses/