Racket is distributed under the MIT license and the Apache version 2.0

license, at your option. However, the Racket runtime system includes

components distributed under other licenses. In short:

* The Racket CS runtime system embeds Chez Scheme, which is

distributed under the Apache version 2.0 license. This runtime

system is built from code in racket/src/cs.

* The Racket BC runtime system includes code distributed under the

GNU Lesser General Public License, version 3. This runtime system

is built from code in racket/src/bc.

Except for Windows executables that are created with the "embed DLLs"

option, the runtime system remains separate as a shared library or

additional executable, which means that it is dynamically linked and

can be replaced with a modified variant by users.

See the file racket/src/LICENSE-LGPL.txt for the full text of the GNU

Lesser General Public License.

See the file racket/src/LICENSE-APACHE.txt for the full text of the

Apache version 2.0 license.

See the file racket/src/LICENSE-MIT.txt for the full text of the

MIT license.

Additionally, the default mode of building Racket will install other

packages, which are distributed under their own license. In the

default mode, all of those packages are distributed under the licenses

listed above.

There may also be other licenses for code within this repository with

which you must comply. Some of them are listed below.

The following are used in all Racket executables:

* mbed TLS. Code from mbed TLS can be found in

racket/src/rktio/rktio_sha2.c. mbed TLS is licensed under the Apache

v2.0 License.

The following are used only in the traditional Racket executable:

* libscheme. Code from libscheme can be found in racket/src/racket.

See the file racket/src/LICENSE-libscheme.txt.

* GNU Lightning. Code from GNU Lightning can be found in

racket/src/racket/src. GNU Lightning is distributed under the GNU

Lesser General Public License version 3.

* GMP. Code from GMP can be found in racket/src/racket/src. The

version of GMP used is distributed under the GNU Lesser General

Public License version 3.

* The Boehm Collector. Code for this package can be found in

racket/src/racket/gc. See the file racket/src/racket/gc/README.QUICK

for license information.

* zlib. Code translated from earlier versions of zlib can be found in

racket/racket/collects/file/{gzip,gunzip}.rkt. Zlib is distributed

under a liberal license, see http://zlib.net/.

* libffi. Code from libffi can be found in racket/src/foreign/libffi.

See racket/src/foreign/libffi/LICENSE.

* libunwind. Code from libunwind can be found in

racket/src/racket/src/unwind.

* random.c. Code from random.c from FreeBSD 2.2 found in

racket/src/racket/src/random.inc.

* install. Code from install can be found in racket/src/lt/install-sh

and is distributed under the MIT license.

* MemoryModule. Code from MemoryModule can be found in

racket/src/start/MemoryModule.c. MemoryModule is distributed under

the MPL v2.0.

The following are used only in benchmarks, and are not part of the

standard Racket distribution:

* psyntax. Code from psyntax can be found in

pkgs/racket-benchmarks/tests/racket/benchmarks/common/psyntax.sch

and is distributed under the Apache v2.0 License.

* SCM. Code from SCM can be found in

pkgs/racket-benchmarks/tests/racket/benchmarks/shootout/pidigits1.rkt

SCM is available under the LGPL.