Xcode 3.2.3 Release was released on 10 Aug 2010 and requires macOS 10.6.2+.
It can be downloaded from https://download.developer.apple.com/ios/ios_sdk_4.0.2__final/xcode_3.2.3_and_ios_sdk_4.0.2.dmg.
The SDKs it contains are:
- iOS 3.2
- iOS 4.0.2
The compilers it contains are:
- clang 1.5 (Build 60)
- LLVM-GCC (Build 2326.10)
- GCC 4.0 (Build 5494)
- GCC 4.2 (Build 5664)