# The Old New Thing (Raymond Chen)

Raymond Chen has been writing The Old New Thing on Microsoft's developer blog network since 2003. He's a longtime Windows developer (originally on the Win95 shell team, later on the broader Windows compatibility group), and the blog's beat is the *why* behind Windows behavior — calling conventions, undocumented kernel internals, why some legacy API does the strange thing it does, what an exotic architecture like Itanium taught compiler writers, how application compatibility shims work.

The blog is a primary source for two things rarely written down elsewhere:

- **Windows-NT-internal archaeology.** Why a particular API was designed a particular way; what the alternative designs were and why they lost; how shipped software pinned a behavior in place.
- **Cross-architecture calling-convention details.** Itanium, Alpha, MIPS, PowerPC, ARM64 — Chen has written extensively about how each handled function calls, prologues, epilogues, register saves, and exception unwinding. The Itanium series in particular is widely cited because it documents quirks Intel's own manuals describe only formally.

URL: <https://devblogs.microsoft.com/oldnewthing/>

## Coverage in the wiki

- [[itanium-too-few-parameters]] — the post on what happens when you pass too few parameters, with the NaT-bit and register-stack-engine details
- [[win32-stable-abi]] — the broader "Win32 is the only stable ABI on Linux" thesis, which leans on Chen's archive for why Windows treats compatibility as a hard constraint
- [[win32-weird-shaped-windows]] — a Chen post on Win32's non-rectangular window shapes