diff --git a/docs/ReleaseNotes.md b/docs/ReleaseNotes.md
index b8b7e22..be6f06e 100644
--- a/docs/ReleaseNotes.md
+++ b/docs/ReleaseNotes.md
@@ -1,43 +1,61 @@
 # cppjit 0.1.0a1 Release Notes
 
 This document contains the release notes for cppjit 0.1.0a1, an
-automatic Python-C++ interoperability and bindings package built on
-[CppInterOp](https://github.com/compiler-research/CppInterOp) and the
-[LLVM](https://llvm.org) compiler infrastructure. If you are reading
-this file from a git checkout, it describes the *next* release, not
-the current one. The notes of previously released versions are
-archived on the
-[releases page](https://github.com/compiler-research/cppjit/releases).
+automatic Python-C++ interoperability layer and bindings generator
+built on [CppInterOp](https://github.com/compiler-research/CppInterOp)
+and the [LLVM](https://llvm.org) compiler infrastructure.
 
 This release supports Python 3.12-3.14 and LLVM 21-22.
 
 ## Highlights
 
-- ...
-
-## New features
-
-- ...
-
-## Deprecated features
-
-- ...
-
-## Backwards incompatible changes
-
-- ...
-
-## Other changes
-
-- ...
+- cppjit 0.1.0a1 is the first prerelease of cppjit, the successor of
+  [cppyy](https://github.com/wlav/cppyy) rebuilt on CppInterOp and the
+  clang-repl C++ interpreter in LLVM.
+- The release installs from PyPI with `pip install cppjit` and ships
+  wheels for Linux x86_64/aarch64 and macOS arm64/x86_64 on Python
+  3.12-3.14, built with the LLVM 21 toolchain.
+- This first prerelease establishes the build system, test, and
+  packaging infrastructure of the new monorepo, with planned
+  improvements, documentation, and benchmarks in the next beta
+  release.
+
+## Changes from cppyy
+
+The user-facing Python layer is mostly unchanged from cppyy: `cppdef`,
+`include`, `gbl`, and the pythonization machinery work as before. The
+changes are in the compiler layer underneath:
+
+- New backend:
+  [CppInterOp](https://github.com/compiler-research/CppInterOp) and
+  the clang-repl incremental compiler replace Cling and its patched
+  LLVM. clang-repl is the upstreamed evolution of Cling, so cppjit
+  builds against stock LLVM releases with no custom patches.
+- Compiler-derived bindings: string-based type lookups give way to
+  opaque handles on the Clang AST, and type conversion and overload
+  resolution follow Clang's own rules.
+- One package: the cppyy, CPyCppyy, and cppyy-backend distribution
+  stack is consolidated into a single package and repository, built
+  with scikit-build-core and published to PyPI through trusted
+  publishing.
+- Supported platforms: CPython 3.12-3.14 on Linux x86_64/aarch64 and
+  macOS arm64/x86_64. cppyy's PyPy support is not carried over.
+  Windows is not supported with this release but is a planned future
+  development
+  ([#89](https://github.com/compiler-research/cppjit/issues/89)).
 
 ## Contributors
 
 Special thanks to everyone who contributed to this release:
 
-- ...
-
-<!-- Contributors since the previous release, with commit counts, in
-alphabetical order:
- git log --pretty='%an' <previous-tag>..HEAD | sort | uniq -c
--->
+- Aaron Jomy
+- Emery Conrad
+- Grigori Rybkine
+- Jonas Rembser
+- Kerem Şahin
+- Vassil Vassilev
+- Vipul Cariappa
+- Wim Lavrijsen
+
+And all past contributors to the now-archived compiler-research
+forks of cppyy, CPyCppyy and cppyy-backend.
diff --git a/python/cppjit/_version.py b/python/cppjit/_version.py
index 3dc1f76..1ac008e 100644
--- a/python/cppjit/_version.py
+++ b/python/cppjit/_version.py
@@ -1 +1 @@
-__version__ = "0.1.0"
+__version__ = "0.1.0a1"