Question

I want to make my C++ project cross platform, and I’m considering using Cygwin/MinGW.
But what is the difference between them ?

Another question is whether I will be able to run the binary on a system without Cygwin/MinGW ?

Answer 1

As a simplification, it’s like this:

• Compile something in Cygwin and you are compiling it for Cygwin.

• Compile something in MinGW and you are compiling it for Windows.

What is Cygwin?

Cygwin is a compatibility layer that makes it easy to port simple Unix-based applications to Windows, by emulating many of the basic interfaces that Unix-based operating systems provide, such as pipes, Unix-style file and directory access, and so on as documented by the POSIX standards. Cygwin is also bundled with a port of the GNU Compiler Collection and some other tools to the Cygwin environment.

If you have existing source code that uses POSIX interfaces, you may be able to compile it for use with Cygwin after making very few or even no changes, greatly simplifying the process of porting simple IO based Unix code for use on Windows.

Disadvantages of Cygwin

Compiling with Cygwin involves linking your program with the Cygwin run-time environment, which will typically be distributed with your program as the dynamically linked library cygwin1.dll. This library is open source and requires software using it to share a compatible open source license, even if you distribute the dll separately, because the header files and interface are included. This therefore imposes some restrictions on how you can license your code.

What is MinGW?

MinGW is a distribution of the GNU compiler tools for native Windows, including the GNU Compiler Collection, GNU Binutils and GNU Debugger. Also included are header files and libraries allowing development of native Windows applications. This therefore will act as an open source alternative to the Microsoft Visual C++ suite.

It may be possible to use MinGW to compile something that was originally intended for compiling with Microsoft Visual C++ with relatively minor modifications.

By default, code compiled in MinGW’s GCC will compile to a native Windows target, including .exe and .dll files, though you could also cross-compile with the right settings, since you are basically using the GNU compiler tools suite.

Even though MingW includes some header files and interface code allowing your code to interact with the Windows API, as with the regular standard libraries this doesn’t impose licensing restrictions on software you have created.

Disadvantages of MinGW

Software compiled for Windows using MinGW has to use Windows’ own API for file and IO access. If you are porting a Unix/Linux application to Windows this may mean significant alteration to the code because the POSIX type API can no longer be used.

Other considerations

For any non-trivial software application, such as one that uses a graphical interface, multimedia or accesses devices on the system, you leave the boundary of what Cygwin can do for you and further work will be needed to make your code cross-platform. But, this task can be simplified by using cross-platform toolkits or frameworks that allow coding once and having your code compile successfully for any platform. If you use such a framework from the start, you can not only reduce your headaches when it comes time to port to another platform but you can use the same graphical widgets – windows, menus and controls – across all platforms if you’re writing a GUI app, and have them appear native to the user.

For instance, the open source Qt framework is a popular and comprehensive cross-platform development framework, allowing the building of graphical applications that work across operating systems including windows. There are other such frameworks too. In addition to the large frameworks there are thousands of more specialized software libraries in existence which support multiple platforms allowing you to worry less about writing different code for different platforms.

When you are developing cross-platform software from the start, you would not normally have any reason to use Cygwin. When compiled on Windows, you would usually aim to make your code able to be compiled with either MingW or Microsoft Visual C/C++, or both. When compiling on Linux/*nix, you’d most often compile it with the GNU compilers and tools directly.