MySQL AB representatives are commonly cited as champions of what they claim to be a "second generation" of open source companies. The revenues of both first and second generation open source companies usually derive from selling support, consulting services, and training for their products. What generally distinguishes this "second generation" of companies, such as MySQL AB and
Trolltech, from earlier "open source"
business models is
dual licensing — the software is supplied under an open source license, but traditional software licences are also sold by the company that owns the software. As an example, MySQL AB makes MySQL available under the
GPL at no charge, but sells it under other more traditional licenses to clients who do not find the GPL to be ideal for their purposes, such as inclusion of MySQL AB technology in a closed source product. Other sources of revenue for MySQL AB were providing support and consulting, as well as training and certification for MySQL Server. Together with some additional services, MySQL also provided a subscription-based product called
MySQL Enterprise, which is also resold by other companies such as
Dell,
HP, and
Novell. ==History==