diff --git a/CMake-OpenWatcom2/.clang-format b/CMake-OpenWatcom2/.clang-format
new file mode 100755
index 0000000..f0fb4b4
--- /dev/null
+++ b/CMake-OpenWatcom2/.clang-format
@@ -0,0 +1,66 @@
+# Generated from CLion C/C++ Code Style settings
+BasedOnStyle: LLVM
+AccessModifierOffset: -1
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: None
+AlignOperands: DontAlign
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Always
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Always
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterReturnType: None
+AlwaysBreakTemplateDeclarations: Yes
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: false
+  AfterControlStatement: Never
+  AfterEnum: false
+  AfterFunction: false
+  AfterNamespace: false
+  AfterUnion: false
+  BeforeCatch: false
+  BeforeElse: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: true
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: BeforeColon
+BreakInheritanceList: BeforeColon
+ColumnLimit: 0
+CompactNamespaces: false
+ContinuationIndentWidth: 4
+IndentCaseLabels: true
+IndentPPDirectives: None
+IndentWidth: 2
+KeepEmptyLinesAtTheStartOfBlocks: true
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: false
+PointerAlignment: Right
+ReflowComments: false
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 0
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+TabWidth: 4
+UseTab: Never
diff --git a/CMake-OpenWatcom2/.idea/.gitignore b/CMake-OpenWatcom2/.idea/.gitignore
new file mode 100755
index 0000000..8ed479c
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/.gitignore
@@ -0,0 +1,9 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
+/deployment.xml
diff --git a/CMake-OpenWatcom2/.idea/.name b/CMake-OpenWatcom2/.idea/.name
new file mode 100644
index 0000000..f0fef4c
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/.name
@@ -0,0 +1 @@
+CMake-OpenWatcom2
diff --git a/CMake-OpenWatcom2/.idea/CMake-OpenWatcom2.iml b/CMake-OpenWatcom2/.idea/CMake-OpenWatcom2.iml
new file mode 100755
index 0000000..f08604b
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/CMake-OpenWatcom2.iml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module classpath="CMake" type="CPP_MODULE" version="4" />
\ No newline at end of file
diff --git a/CMake-OpenWatcom2/.idea/custom-compiler.xml b/CMake-OpenWatcom2/.idea/custom-compiler.xml
new file mode 100755
index 0000000..80acd1b
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/custom-compiler.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="com.jetbrains.cidr.lang.workspace.compiler.custom.CustomCompilerService">
+    <option name="definitionsFile" value="$PROJECT_DIR$/openwatcom2.yaml" />
+    <option name="enabled" value="true" />
+  </component>
+</project>
diff --git a/CMake-OpenWatcom2/.idea/misc.xml b/CMake-OpenWatcom2/.idea/misc.xml
new file mode 100755
index 0000000..79b3c94
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/misc.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
+</project>
\ No newline at end of file
diff --git a/CMake-OpenWatcom2/.idea/modules.xml b/CMake-OpenWatcom2/.idea/modules.xml
new file mode 100755
index 0000000..6e7bf54
--- /dev/null
+++ b/CMake-OpenWatcom2/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/CMake-OpenWatcom2.iml" filepath="$PROJECT_DIR$/.idea/CMake-OpenWatcom2.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/CMake-OpenWatcom2/CMakeLists.txt b/CMake-OpenWatcom2/CMakeLists.txt
new file mode 100755
index 0000000..bcb0271
--- /dev/null
+++ b/CMake-OpenWatcom2/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.21)
+project(CMake-OpenWatcom2 C)
+
+set(CMAKE_C_STANDARD 90)
+
+add_executable(CMake-OpenWatcom2 main.c)
diff --git a/CMake-OpenWatcom2/README.md b/CMake-OpenWatcom2/README.md
new file mode 100644
index 0000000..727fa7a
--- /dev/null
+++ b/CMake-OpenWatcom2/README.md
@@ -0,0 +1,66 @@
+## Custom compiler definitions for CLion and OpenWatcom 2
+
+This compiler definition allows you to use OpenWatcom 2 from Linux or Windows.
+
+## Supported platforms
+
+- Windows NT (x86)
+- 16-bit OS/2
+- 32-bit OS/2
+- DOS
+- 32-bit DOS (using DOS/4GW)
+- Linux (x86)
+
+## Unsupported platforms
+
+- 16-bit Windows: don't know how to make it work, patches welcome
+- Windows for MIPS, PowerPC or Alpha: the compilers are there, but the libraries are not made, contribute to [Open Watcom 2](https://github.com/open-watcom/open-watcom-v2) to make it possible
+- QNX: headers and libraries are copyright of BlackBerry Limited, ping them for opensourcing them (as they were for QNX 2 and QNX 4 probably not of much interest to them anymore?)
+- NetWare: libraries are there but headers need to be installed separately, ping Micro Focus International for opensourcing them (as they abandoned NetWare long ago)
+- Others: Watcom supported many targets over the ages and I don't know which others may just need some care to make them work
+
+## Instructions
+
+The most important step is to ensure that Watcom binaries are in the path. This depends on your exact installation but usually on Windows it is `C:\WATCOM\BINNT64` and on Linux it is `/opt/watcom/binl64`. Until JetBrains allow to specify APPENDING path members for a specific toolchain (tried with Environment Variables, no go) this is a must.
+
+After this is done you need to add the compilers in `Settings -> Build, Execution, Deployment -> Toolchains` and set up at least the C compiler and C++ compiler (they're the same) and at least in Windows (as there's no system `make` to make CLion happy) also select `wmake` (`wmake.exe`).
+
+Compiler for 16-bit targets: `wcl` or `wcl.exe`
+Compiler for 32-bit targets: `wcl386` or `wcl386.exe`
+Compiler for Alpha targets: `wclaxp` or `wclaxp.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+Compiler for MIPS targets: `wclmps` or `wclmps.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+Compiler for PowerPC targets: `wclppc` or `wclppc.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+
+Then, for the project, you need to go `Settings -> Build, Execution, Deployment -> CMake` and create the appropriate targets.
+
+In each target set the following environment for Windows (change paths appropriately if installed in another location):
+
+- `WATCOM=C:\WATCOM`
+- `INCLUDE=C:\WATCOM\H\;C:\WATCOM\H\NT\;C:\WATCOM\H\NT\DIRECTX\;C:\WATCOM\H\NT\DDK\;%INCLUDE%`
+
+or in Linux (change paths appropriately if installed in another location):
+
+- `WATCOM=/opt/watcom`
+- `INCLUDE=/opt/watcom/lh`
+
+then in CMake options you need to set: `-DCMAKE_SYSTEM_NAME=<system> -DCMAKE_SYSTEM_PROCESSOR=<arch> -G "Watcom WMake"`
+
+where `<system>` is:
+
+- `DOS` for DOS
+- `OS2` for OS/2
+- `Windows` for Windows and Windows NT
+- `Linux` for Linux
+
+and `<arch>` is:
+
+- `I86` for 16-bit
+- `I386` for 32-bit
+- none for 32-bit or the others *(untested)*
+
+## Final notes
+
+The preprocessor macros have been a bestguess and may be severely incomplete, patches welcome!
+
+2021 - [Natalia Portillo](https://github.com/claunia)
+Many thanks to [Jiří Malák](https://github.com/jmalak) for keeping OpenWatcom alive!
diff --git a/CMake-OpenWatcom2/main.c b/CMake-OpenWatcom2/main.c
new file mode 100755
index 0000000..0923337
--- /dev/null
+++ b/CMake-OpenWatcom2/main.c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main() {
+  printf("Hello, World!\n");
+  return 0;
+}
diff --git a/CMake-OpenWatcom2/openwatcom2.yaml b/CMake-OpenWatcom2/openwatcom2.yaml
new file mode 100755
index 0000000..4b8a251
--- /dev/null
+++ b/CMake-OpenWatcom2/openwatcom2.yaml
@@ -0,0 +1,105 @@
+
+compilers:
+
+  - description: OpenWatcom 32-bit OS/2 target
+    match-args: "-bt=os2"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os2"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __OS2__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit DOS target
+    match-args: "-bt=dos"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os2"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define _DOS 1
+#define MSDOS 1
+#define __DOS__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit Windows target
+    match-args: "-bt=nt"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/nt"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __NT__ 1
+#define __WINDOWS_386__ 1
+#define _WIN32 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 16-bit OS/2 target
+    match-args: "-bt=os2"
+    match-compiler-exe: "(.*/)?wcl(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os21x"
+    defines-text: "
+#define __X86__ 1
+#define __I86__ 1
+#define M_I86 1
+#define _M_I86 1
+#define _M_IX86 0
+#define __OS2__ 1
+#define __LARGE__ 1
+#define M_I86LM 1
+#define _M_I86LM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom DOS target
+    match-args: "-bt=dos"
+    match-compiler-exe: "(.*/)?wcl(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h"
+    defines-text: "
+#define __X86__ 1
+#define __I86__ 1
+#define M_I86 1
+#define _M_I86 1
+#define _M_IX86 0
+#define __DOS__ 1
+#define _DOS 1
+#define MSDOS 1
+#define __LARGE__ 1
+#define M_I86LM 1
+#define _M_I86LM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit Linux target
+    match-args: "-bt=linux"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/nt"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __LINUX__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
diff --git a/README.md b/README.md
index 132bab7..036a891 100644
--- a/README.md
+++ b/README.md
@@ -24,4 +24,10 @@ This repository contains:
     * Compiler definition file: [custom-compiler-sdcc-stm8.yaml](CCMake-SDCC/custom-compiler-sdcc-stm8.yaml)
   * Host Platforms: Windows, Linux, Mac
   * Target Platform: STM8 MCU
-  
\ No newline at end of file
+* [CMake-OpenWatcom2](CMake-OpenWatcom2)
+  * Build System: [CMake](https://cmake.org/)
+  * Compiler: [Open Watcom 2](https://github.com/open-watcom/open-watcom-v2)
+    * Compiler definition file: [openwatcom2.yaml](CMake-OpenWatcom2/openwatcom2.yaml)
+  * Host Platforms: Windows, Linux
+  * Target Platform: Windows NT, DOS, 32-bit DOS (DOS/4GW), 16-bit OS/2, 32-bit OS/2, Linux/x86
+  * Contributed by: [Natalia Portillo](https://github.com/claunia)  
diff --git a/configs/OpenWatcom 2/README.md b/configs/OpenWatcom 2/README.md
new file mode 100644
index 0000000..727fa7a
--- /dev/null
+++ b/configs/OpenWatcom 2/README.md	
@@ -0,0 +1,66 @@
+## Custom compiler definitions for CLion and OpenWatcom 2
+
+This compiler definition allows you to use OpenWatcom 2 from Linux or Windows.
+
+## Supported platforms
+
+- Windows NT (x86)
+- 16-bit OS/2
+- 32-bit OS/2
+- DOS
+- 32-bit DOS (using DOS/4GW)
+- Linux (x86)
+
+## Unsupported platforms
+
+- 16-bit Windows: don't know how to make it work, patches welcome
+- Windows for MIPS, PowerPC or Alpha: the compilers are there, but the libraries are not made, contribute to [Open Watcom 2](https://github.com/open-watcom/open-watcom-v2) to make it possible
+- QNX: headers and libraries are copyright of BlackBerry Limited, ping them for opensourcing them (as they were for QNX 2 and QNX 4 probably not of much interest to them anymore?)
+- NetWare: libraries are there but headers need to be installed separately, ping Micro Focus International for opensourcing them (as they abandoned NetWare long ago)
+- Others: Watcom supported many targets over the ages and I don't know which others may just need some care to make them work
+
+## Instructions
+
+The most important step is to ensure that Watcom binaries are in the path. This depends on your exact installation but usually on Windows it is `C:\WATCOM\BINNT64` and on Linux it is `/opt/watcom/binl64`. Until JetBrains allow to specify APPENDING path members for a specific toolchain (tried with Environment Variables, no go) this is a must.
+
+After this is done you need to add the compilers in `Settings -> Build, Execution, Deployment -> Toolchains` and set up at least the C compiler and C++ compiler (they're the same) and at least in Windows (as there's no system `make` to make CLion happy) also select `wmake` (`wmake.exe`).
+
+Compiler for 16-bit targets: `wcl` or `wcl.exe`
+Compiler for 32-bit targets: `wcl386` or `wcl386.exe`
+Compiler for Alpha targets: `wclaxp` or `wclaxp.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+Compiler for MIPS targets: `wclmps` or `wclmps.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+Compiler for PowerPC targets: `wclppc` or `wclppc.exe` *DOESN'T INCLUDE C OR C++ LIBRARIES*
+
+Then, for the project, you need to go `Settings -> Build, Execution, Deployment -> CMake` and create the appropriate targets.
+
+In each target set the following environment for Windows (change paths appropriately if installed in another location):
+
+- `WATCOM=C:\WATCOM`
+- `INCLUDE=C:\WATCOM\H\;C:\WATCOM\H\NT\;C:\WATCOM\H\NT\DIRECTX\;C:\WATCOM\H\NT\DDK\;%INCLUDE%`
+
+or in Linux (change paths appropriately if installed in another location):
+
+- `WATCOM=/opt/watcom`
+- `INCLUDE=/opt/watcom/lh`
+
+then in CMake options you need to set: `-DCMAKE_SYSTEM_NAME=<system> -DCMAKE_SYSTEM_PROCESSOR=<arch> -G "Watcom WMake"`
+
+where `<system>` is:
+
+- `DOS` for DOS
+- `OS2` for OS/2
+- `Windows` for Windows and Windows NT
+- `Linux` for Linux
+
+and `<arch>` is:
+
+- `I86` for 16-bit
+- `I386` for 32-bit
+- none for 32-bit or the others *(untested)*
+
+## Final notes
+
+The preprocessor macros have been a bestguess and may be severely incomplete, patches welcome!
+
+2021 - [Natalia Portillo](https://github.com/claunia)
+Many thanks to [Jiří Malák](https://github.com/jmalak) for keeping OpenWatcom alive!
diff --git a/configs/OpenWatcom 2/openwatcom2.yaml b/configs/OpenWatcom 2/openwatcom2.yaml
new file mode 100755
index 0000000..4b8a251
--- /dev/null
+++ b/configs/OpenWatcom 2/openwatcom2.yaml	
@@ -0,0 +1,105 @@
+
+compilers:
+
+  - description: OpenWatcom 32-bit OS/2 target
+    match-args: "-bt=os2"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os2"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __OS2__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit DOS target
+    match-args: "-bt=dos"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os2"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define _DOS 1
+#define MSDOS 1
+#define __DOS__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit Windows target
+    match-args: "-bt=nt"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/nt"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __NT__ 1
+#define __WINDOWS_386__ 1
+#define _WIN32 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 16-bit OS/2 target
+    match-args: "-bt=os2"
+    match-compiler-exe: "(.*/)?wcl(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/os21x"
+    defines-text: "
+#define __X86__ 1
+#define __I86__ 1
+#define M_I86 1
+#define _M_I86 1
+#define _M_IX86 0
+#define __OS2__ 1
+#define __LARGE__ 1
+#define M_I86LM 1
+#define _M_I86LM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom DOS target
+    match-args: "-bt=dos"
+    match-compiler-exe: "(.*/)?wcl(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h"
+    defines-text: "
+#define __X86__ 1
+#define __I86__ 1
+#define M_I86 1
+#define _M_I86 1
+#define _M_IX86 0
+#define __DOS__ 1
+#define _DOS 1
+#define MSDOS 1
+#define __LARGE__ 1
+#define M_I86LM 1
+#define _M_I86LM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"
+  - description: OpenWatcom 32-bit Linux target
+    match-args: "-bt=linux"
+    match-compiler-exe: "(.*/)?wcl386(\\.exe)?"
+    include-dirs: "${compiler-exe-dir}/../h ${compiler-exe-dir}/../h/nt"
+    defines-text: "
+#define __X86__ 1
+#define __386__ 1
+#define M_I386 1
+#define _M_I386 1
+#define _M_IX86 500
+#define __LINUX__ 1
+#define __FLAT__ 1
+#define M_386FM 1
+#define _M_386FM 1
+#define __WATCOMC__ 1280
+#define _INTEGRAL_MAX_BITS 64"