Split third-party notices out of LICENSE so GitHub detects MIT

LICENSE

@@ -19,29 +19,3 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-
-===============================================
-
-Third Party Licenses:
-
-The Redis project (https://redis.io/) is independent of this client library, and
-is licensed separately under the three clause BSD license. The full license
-information can be viewed here: https://redis.io/topics/license
-
-This tool makes use of the "redis-doc" library from https://redis.io/documentation
-in the intellisense comments, which is licensed under the
-Creative Commons Attribution-ShareAlike 4.0 International license; full
-details are available here:
-https://github.com/antirez/redis-doc/blob/master/COPYRIGHT
-
-The development solution uses the Redis-64 package from nuget
-(https://www.nuget.org/packages/Redis-64) by Microsoft Open Technologies, inc.
-This is licensed under the BSD license; full details are available here:
-https://github.com/MSOpenTech/redis/blob/2.6/license.txt
-This tool is not used in the release binaries.
-
-The development solution uses the BookSleeve package from nuget
-(https://code.google.com/p/booksleeve/) by Marc Gravell. This is licensed
-under the Apache 2.0 license; full details are available here:
-https://www.apache.org/licenses/LICENSE-2.0
-This tool is not used in the release binaries.

THIRD-PARTY-NOTICES.md

@@ -0,0 +1,49 @@
+# Third-party notices
+
+StackExchange.Redis and RESPite are released under the MIT license; see [LICENSE](LICENSE).
+The notes below concern third-party projects and materials referenced by, or incorporated
+into, this repository.
+
+## Redis and other RESP servers
+
+The Redis project (https://redis.io/) is independent of this client library and is licensed
+separately. Redis 7.2 and earlier are licensed under the three-clause BSD license; Redis 7.4
+and later are available under the Redis Source Available License v2 (RSALv2) or the Server
+Side Public License v1 (SSPLv1), and Redis 8.0 and later additionally under the GNU Affero
+General Public License v3 (AGPLv3). The current terms are published at
+https://redis.io/legal/licenses/
+
+Other RESP-compatible servers that this library can connect to (Valkey, Garnet, Dragonfly,
+KeyDB, Azure Managed Redis, AWS ElastiCache, and others) are separate projects and products,
+each licensed by its own maintainer or vendor.
+
+## Redis documentation
+
+The IntelliSense (XML documentation) comments on the command methods draw on the Redis command
+documentation, originally published by the "redis-doc" project, which is licensed under the
+Creative Commons Attribution-ShareAlike 4.0 International license:
+https://github.com/redis/redis-doc (archived; see its COPYRIGHT and LICENSE files).
+
+The current Redis documentation lives at https://redis.io/docs/latest/ and is maintained at
+https://github.com/redis/docs, whose newer content is licensed under Creative Commons
+Attribution-NonCommercial-ShareAlike 4.0 International; see that repository's LICENSE file.
+
+## Code incorporated from other projects
+
+The following source files contain code copied or adapted from other projects; the original
+license notices are preserved in the files themselves.
+
+- `src/RESPite/Shared/NullableHacks.cs` - nullable-annotation attributes for down-level target
+  frameworks, from dotnet/runtime (`NullableAttributes.cs`); .NET Foundation, MIT license.
+- `src/StackExchange.Redis/TaskExtensions.cs` (`TimeoutAfter`) - adapted from
+  `TaskTimeoutExtensions.cs` in dotnet/corefx; .NET Foundation, MIT license.
+- `src/StackExchange.Redis/Format.cs` (`TryParseEndPoint`) - adapted from `IPEndPointParser`
+  in aspnet/BasicMiddleware (Microsoft.AspNetCore.HttpOverrides); .NET Foundation,
+  Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0).
+
+## Test-only material
+
+The test project includes `tests/StackExchange.Redis.Tests/Helpers/redis-sharp.cs`, a copy of
+redis-sharp by Miguel de Icaza (https://github.com/migueldeicaza/redis-sharp), Copyright 2010
+Novell, Inc., licensed under the new BSD license. It is used only as a comparison
+implementation in tests and is not part of the release binaries.