Pine is now Alpine, and is properly open source. Pine is the University of Washington's most excellent email client, and is still one of the fastest and most mature email readers out there. It's a terminal application, has a standalone version (not a terminal, but the same interface in a local window) for Windows, and now with Alpine includes the UW's web version as well. Alpine 1.0 is released under the Apache License 2.0.

Pine also included Pico, Pine's internal text editor as a standalone application and also one of the best lightweight terminal-based text edtiors. The lack of an open source license inspired Nano, an open source re-implementation of Pico found in many Linux distributions. (Type which nano and which pico to see which is installed on your system.) Pico can also be found by default on Mac OS X (though not Pine, strangely).

Alpine also includes proper automake build files, finally.

According to the Alpine story, the extreme lateness of an open source release of Pine was caused by the project's "trademark obligation" to the University, and, I gather, a lack of will in the administration. Other motions towards open source licensing and the decision to rename the product allowed for this release.