Apache License
The Apache Software License is an open source license used by the Apache Software Foundation. The programs released under this license include the Apache web server and various of its modules, the ant Java build tool, the Apache Axis SOAP implementation, the Jakarta Tomcat Java servlet and JSP container, the Apache Xindice database server, the AxKit XML application server, the JXTA peer-to-peer framework, the Xalan XSLT processor, the Xerces XML parser, and the Subversion version control system. The Apache license (version 1.1) requires preservation of the copyright notice and disclaimer, but allows use and distribution of the source code in both open source and closed source software.
The GNU project considers all versions of the Apache License incompatible with the GNU General Public License.