What Is Cygwin? Cygwin is a Linux-like environment for Windows. It consists of two parts:

The latest net releases of the Cygwin DLL are numbered 1.n.x, where "n" is currently "5" (e.g., 1.5.25). Any Cygwin program built from December 1998 onward should work correctly with 1.n.x DLLs.

The 1.n.x version numbering refers only to the Cygwin DLL. Individual packages like bash, gcc, less, etc. are released independently of the DLL. The setup.exe utility tracks the versions of all installed components and provides the mechanism for installing or updating everything available from this site for Cygwin.

The signature for setup.exe can be used to verify the validity of this binary using this public key.

Run setup.exe any time you want to update or install a Cygwin package.

Note that, when installing packages for the first time, setup.exe does not install every package. Only the minimal base packages from the Cygwin distribution are installed by default. Clicking on categories and packages in the setup.exe package installation screen will provide you with the ability to control what is installed or updated. Clicking on the "Default" field next to the "All" category will provide you with the opportunity to install every Cygwin package. Be advised that this will download and install hundreds of megabytes to your computer. The best plan is probably to click on individual categories and install either entire categories or packages from the categories themselves.

Once you've installed your desired subset of the Cygwin distribution, setup.exe will remember what you selected so rerunning the program will update your system with any new package releases.

NOTE: We're in beta-testing for the new Cygwin release 1.7. This new release will come with many changes and a whole bunch of new features.

If you would like to participate in the testing, just download the new setup-1.7.exe and use that setup tool to install Cygwin 1.7. Please note that Cygwin 1.7 will NOT run anymore on Windows 95, 98 or Me.

We also have a new User's Guide for 1.7, which is currently located at http://cygwin.com/1.7/cygwin-ug-net/cygwin-ug-net.html.

We also have new matching API documentation located at http://cygwin.com/1.7/cygwin-api/cygwin-api.html.

And, last but not least, we have a new FAQ, though very likely not quite complete since we still don't know what exactly is a FAQ related to Cygwin 1.7: http://cygwin.com/1.7/faq/faq.html.

Every couple of days the Beta release 1.7.0 is updated with a version including the latest bugfixes and changes. Announcements for these updates are sent to the Cygwin mailing list and the Cygwin-Announce mailing list.

If nothing goes overly wrong, the official 1.7.1 release goes public still within the the first half of 2009.

Please keep in mind that this is a TEST release. Don't use in critical production environments. Nevertheless I'd like to encourage everyone to give 1.7 a try. Due to internal changes it is possible to install a 1.7 release in parallel to a 1.5 release and even run 1.7 processes in parallel to 1.5 processes. The processes will not know about each other! Any try to interact between 1.7-based and 1.5-based processes will lead to, at least, funny results.

To install a 1.7 release in parallel to a 1.5 release, all you have to do is to choose another root directory (for instance: C:\cygwin-1.7) in setup-1.7's "Choose Installation Directory" dialog.

NOTE: Due to the way setup-1.7 works, you have to change the directory right the first time you visit this dialog! If you pressed the "Next" button and then "Back" again, it's already too late and setup-1.7 will create a broken 1.7 install. If you pressed "Next" by mistake, exit setup-1.7 and start it again.

Please report bugs and problems to the Cygwin mailing list and, thanks for your participation.