The ISO code had a restrictive license but was available without charge.

The most restrictive licenses require any code that touches an open-source program to be made available freely.

In January 2002 Radiance 3.4 was relicensed under a less restrictive license.

However, the SWF specification was released under a very restrictive license:

They also added a restrictive click-thru license to their styles download web site.

The change in license over time, from a permissive open source license to a restrictive dual license, caused controversy in the Ext user community.

This ensures integration into printed materials, websites and applications is possible, without being limited by restrictive licenses, or having to pay fees.

Since then, the (SDA) has provided a simplified version of the specification under a less restrictive license.

Until 2008, the use of Flash was covered by restrictive licenses.

Confusion may arise when a person outside the company creates additional source code, using the less restrictive license.