# Using SWI-Prolog for commercial applications

SWI-Prolog is being used for commercial applications. The [license
conditions](</license.html>) allow for embedding in commercial
applications without restrictions on the license conditions for the
proprietary code.

We welcome commercial usage of the system.  Commercial users have
had a major impact on the system by sponsoring the
development.  Examples of *sponsored* features and components are:

  - The initial garbage collector
  - Unbound integer and rational number support
  - The [PlDoc](</pldoc/package/pldoc.html>) documentation system
  - The [PlUnit](</pldoc/package/plunit.html>) testing system
  - The [SSL](</pldoc/package/ssl.html>) interface
  - Redesign of the (stack) memory management to avoid using
    the C stack for recursive traversal of Prolog terms, make
    threads more memory efficient and remove the limitation of
    the number of threads.

Commercial users have greatly helped in *debugging* several features,
notably multi-threading support and the
[ODBC](</pldoc/package/odbc.html>) interface.

Finally, commercial users have *provided packages*.  While making your
package available requires an investment, you get a pay-back because
others will help you to debug it and clean the interfaces.  Examples of
such packages are:

  - The [JPL](</packages/jpl/>) Java interface.
  - The [TIPC](</pldoc/package/tipc.html>) networking interface.
  - The [Google protocol buffers](</pldoc/package/protobufs.html>)
    interface.
  - The [CQL](</pldoc/man?section=cql>) library

Involvement of commercial users is vital to the project!