Dual Licensing in the Open Source Software Industry
* Article: Dual Licensing in Open Source Software Industry. By Mikko Välimäki. Systemes d´Information et Management, Vol. 8, No. 1, pp. 63-75, 2003.
"This paper analyses how several open source companies use Dual Licensing: both open source and proprietary licenses for one product. Three case studies based on the experiences of companies Sleepycat Software Inc., MySQL AB, and TrollTech AS illustrate the issue. Especially the legal and economic requirements of dual licensing are identified."