At some point the meaning of the Xcode version list under "Note on Xcode versions" changed to SDK versions instead of "runs" as the intro says

Author: Blzut3

README.md

@@ -1,7 +1,7 @@
 XcodeLegacy
 ===========
 
-Legacy components for Xcode 4-10 (deprecated compilers and Mac OS X SDKs).
+Legacy components for Xcode 4-12 (deprecated compilers and Mac OS X SDKs).
 
 Home page: https://github.com/devernay/xcodelegacy
 
@@ -10,7 +10,7 @@ Description
 
 Many components were removed in recent versions of Xcode, the most notable being the Mac OS X 10.6 SDK, which is required to build software using the Carbon API (such as wxWidgets 2.8).
 
-I made the script XcodeLegacy.sh to extract these components (the links work if you [sign in to Apple Developer](https://developer.apple.com/downloads/) first) from [Xcode 3.2.6](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.2.6_and_ios_sdk_4.3__final/xcode_3.2.6_and_ios_sdk_4.3.dmg) (10.4, 10.5 and 10.6 SDKs, PPC assembler, GCC 4.0 and 4.2, LLVM-GCC 4.2), [Xcode 4.6.3](https://download.developer.apple.com/Developer_Tools/xcode_4.6.3/Xcode_4.6.3.dmg) (10.7 SDK), [Xcode 5.1.1](https://download.developer.apple.com/Developer_Tools/xcode_5.1.1/Xcode_5.1.1.dmg) (10.8 SDK), [Xcode 6.4](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_6.4/Xcode_6.4.dmg) (10.9 and 10.10 SDKs), [Xcode 7.3.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_7.3.1/Xcode_7.3.1.dmg) (10.11 SDK), [Xcode 8.3.3](https://download.developer.apple.com/Developer_Tools/Xcode_8.3.3/Xcode_8.3.3.xip) (10.12 SDK), [Xcode 9.4.1](https://download.developer.apple.com/Developer_Tools/Xcode_9.4.1/Xcode_9.4.1.xip) (10.13 SDK), [Xcode 10.3](https://download.developer.apple.com/Developer_Tools/Xcode_10.3/Xcode_10.3.xip) (10.14 SDK), [Xcode 12.1](https://download.developer.apple.com/Developer_Tools/Xcode_12.1/Xcode_12.1.xip) (10.15 SDK), and install them in Xcode 4-10:
+I made the script XcodeLegacy.sh to extract these components (the links work if you [sign in to Apple Developer](https://developer.apple.com/downloads/) first) from [Xcode 3.2.6](https://download.developer.apple.com/Developer_Tools/xcode_3.2.6_and_ios_sdk_4.3__final/xcode_3.2.6_and_ios_sdk_4.3.dmg) (10.4, 10.5 and 10.6 SDKs, PPC assembler, GCC 4.0 and 4.2, LLVM-GCC 4.2), [Xcode 4.6.3](https://download.developer.apple.com/Developer_Tools/xcode_4.6.3/Xcode_4.6.3.dmg) (10.7 SDK), [Xcode 5.1.1](https://download.developer.apple.com/Developer_Tools/xcode_5.1.1/Xcode_5.1.1.dmg) (10.8 SDK), [Xcode 6.4](https://download.developer.apple.com/Developer_Tools/Xcode_6.4/Xcode_6.4.dmg) (10.9 and 10.10 SDKs), [Xcode 7.3.1](https://download.developer.apple.com/Developer_Tools/Xcode_7.3.1/Xcode_7.3.1.dmg) (10.11 SDK), [Xcode 8.3.3](https://download.developer.apple.com/Developer_Tools/Xcode_8.3.3/Xcode_8.3.3.xip) (10.12 SDK), [Xcode 9.4.1](https://download.developer.apple.com/Developer_Tools/Xcode_9.4.1/Xcode_9.4.1.xip) (10.13 SDK), [Xcode 10.3](https://download.developer.apple.com/Developer_Tools/Xcode_10.3/Xcode_10.3.xip) (10.14 SDK), [Xcode 12.1](https://download.developer.apple.com/Developer_Tools/Xcode_12.1/Xcode_12.1.xip) (10.15 SDK), and install them in Xcode 4-10:
 
 - GCC 4.0, GCC 4.2 and LLVM GCC 4.2 compilers
 - GCC 4.0, GCC 4.2 and LLVM GCC 4.2 Xcode plugins
@@ -101,28 +101,28 @@ The script also fixes the Mac OS X 10.4 SDK so that it works with GCC 4.2 and LL
 
 PowerPC architectures (ppc, ppc7400, ppc970, ppc64) cannot be linked for OS X 10.7 or newer (they would be useless anyway, since PowerPC CPUs were only supported up to 10.5).
 
+GCC 4.0 is a 32-bit binary, so it will not be installed on macOS 10.15 or newer. GCC 4.2 is 64-bit and continues to work.
 
 Note on Xcode versions
 ----------------------
 
 Here are the latest versions of Xcode that are known to /run/ on each OS X version (the links work if you [sign in to Apple Developer](https://developer.apple.com/downloads/) first):
 
-- [Xcode 2.5](http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_2.5_developer_tools/xcode25_8m2558_developerdvd.dmg) on Mac OS X 10.4 (Tiger) (*)
-- [Xcode 3.1.4](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.1.4_developer_tools/xcode314_2809_developerdvd.dmg) on Mac OS X 10.5 (Leopard) (*)
-- [Xcode 3.2.6](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.2.6_and_ios_sdk_4.3__final/xcode_3.2.6_and_ios_sdk_4.3.dmg) on Mac OS X 10.6 (Snow Leopard) - [Xcode 4.0.2](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.0.2_and_ios_sdk_4.3/xcode_4.0.2_and_ios_sdk_4.3.dmg), [Xcode 4.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.1_for_snow_leopard_21110/xcode_4.1_for_snow_leopard.dmg) and [Xcode 4.2](https://download.developer.apple.com/Developer_Tools/xcode_4.2_for_snow_leopard/xcode_4.2_for_snow_leopard.dmg) also run on Snow Leopard, but are only available to pay members (*)
+- [Xcode 2.5](https://download.developer.apple.com/Developer_Tools/xcode_2.5_developer_tools/xcode25_8m2558_developerdvd.dmg) on Mac OS X 10.4 (Tiger) (*)
+- [Xcode 3.1.4](https://download.developer.apple.com/Developer_Tools/xcode_3.1.4_developer_tools/xcode314_2809_developerdvd.dmg) on Mac OS X 10.5 (Leopard) (*)
+- [Xcode 3.2.6](https://download.developer.apple.com/Developer_Tools/xcode_3.2.6_and_ios_sdk_4.3__final/xcode_3.2.6_and_ios_sdk_4.3.dmg) on Mac OS X 10.6 (Snow Leopard) - [Xcode 4.2](https://download.developer.apple.com/Developer_Tools/xcode_4.2_for_snow_leopard/xcode_4.2_for_snow_leopard.dmg) also runs on Snow Leopard, but are only available to pay members (*)
 - [Xcode 4.6.3](https://download.developer.apple.com/Developer_Tools/xcode_4.6.3/Xcode_4.6.3.dmg) on OS X 10.7 (Lion)
 - [Xcode 5.1.1](https://download.developer.apple.com/Developer_Tools/xcode_5.1.1/Xcode_5.1.1.dmg) on OS X 10.8 (Mountain Lion)
-- [Xcode 6.2](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_6.2/Xcode_6.2.dmg) on OS X 10.9 (Mavericks)
-- [Xcode 7.2.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_7.2.1/Xcode_7.2.1.dmg) on OS X 10.10 (Yosemite)
-- [Xcode 7.3.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_7.3.1/Xcode_7.3.1.dmg) on OS X 10.11 (El Capitan), please see note on linking below. [Xcode 8.2.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_8.2.1/Xcode_8.2.1.xip) (**) also runs on OS X 10.11, but can only compile for macOS 10.12.
-- [Xcode 8.3.3](https://download.developer.apple.com/Developer_Tools/Xcode_8.3.3/Xcode_8.3.3.xip) on macOS 10.12 (Sierra), please see note on linking below. (**)
-- [Xcode 9.4.1](https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_9.4.1/Xcode_9.4.1.xip) on macOS 10.13 (High Sierra), please see note on linking below. (**)
-- [Xcode 10.3](https://download.developer.apple.com/Developer_Tools/Xcode_10.3/Xcode_10.3.xip) on macOS 10.14 (Mojave), please see note on linking below.
-- [Xcode 12.1](https://download.developer.apple.com/Developer_Tools/Xcode_12.1/Xcode_12.1.xip) on macOS 10.15 (Catalina), please see note on linking below.
+- [Xcode 6.2](https://download.developer.apple.com/Developer_Tools/Xcode_6.2/Xcode_6.2.dmg) on OS X 10.9 (Mavericks)
+- [Xcode 7.2.1](https://download.developer.apple.com/Developer_Tools/Xcode_7.2.1/Xcode_7.2.1.dmg) on OS X 10.10 (Yosemite)
+- [Xcode 8.2.1](https://download.developer.apple.com/Developer_Tools/Xcode_8.2.1/Xcode_8.2.1.xip) on OS X 10.11 (El Capitan)
+- [Xcode 9.2](https://download.developer.apple.com/Developer_Tools/Xcode_9.2/Xcode_9.2.xip) on macOS 10.12 (Sierra), please see note on linking below. (**)
+- [Xcode 10.1](https://download.developer.apple.com/Developer_Tools/Xcode_10.1/Xcode_10.1.xip) on macOS 10.13 (High Sierra), please see note on linking below. (**)
+- [Xcode 11.3.1](https://download.developer.apple.com/Developer_Tools/Xcode_11.3.1/Xcode_11.3.1.xip) on macOS 10.14 (Mojave), please see note on linking below.
 
 (*) These Xcode versions were released before 26.03.2012 and may cause an "An unknown installation error" during installation, which is due to an expired certificate. Installing these may require disabling network time sync and setting the date to 01.01.2012 before installing. Network time sync may be re-enabled after install. See [this stackexchange question](https://apple.stackexchange.com/questions/45841/xcode-4-2-snow-leopard-doesnt-install) for more details.
 
- (**) If you downloaded these Xcode versions (8.2.1, 8.3.3, 9.4.1) before 24th October 2019 the certificate used to sign them has expired and Archive Utility will refuse to unpack them. See [this TidBITS article](https://tidbits.com/2019/10/28/redownload-archived-macos-installers-to-address-expired-certificates/) which describes the same problem in OS installers for more details. XcodeLagacy now checks for this problem and prompts you to re-download the archives which now have updated signatures.
+ (**) If you downloaded these Xcode versions (8.2.1, 8.3.3, 9.2, 9.4.1, 10.1) before 24th October 2019 the certificate used to sign them has expired and Archive Utility will refuse to unpack them. See [this TidBITS article](https://tidbits.com/2019/10/28/redownload-archived-macos-installers-to-address-expired-certificates/) which describes the same problem in OS installers for more details. XcodeLagacy now checks for this problem and prompts you to re-download the archives which now have updated signatures.
 
 More information about the compilers included in each version of Xcode can be found on the [MacPorts Wiki](https://trac.macports.org/wiki/XcodeVersionInfo) and on [Wikipedia](https://en.wikipedia.org/wiki/Xcode).