Xcode 3.2.1 Release was released on 7 Oct 2009 and requires macOS 10.6+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/xcode_3.2.1_developer_tools/xcode321_10m2003_developerdvd.dmg.
Release notes are located at https://download.developer.apple.com/Developer_Tools/xcode_3.2.1_developer_tools/about_xcode_3.2.1.pdf.
The compilers it contains are:
- LLVM-GCC (Build 2206)
- GCC 4.0 (Build 5493)
- GCC 4.2 (Build 5646)