If you are affiliated with another university that has purchased a site license for Trees, please contact your instructor for download instructions.
The latest version of the tree drawing tool for use with Trees 3 is version 1.2.2. Download by clicking here.
Trees is a computer program (© Sean Crist and Anthony Kroch) that helps students learn the basics of syntactic structure and transformational derivations. The program is used in courses at the University of Pennsylvania and elsewhere. It is also used for drawing trees for display in word processing documents and on web pages.
Trees was developed under a grant from the University of Pennsylvania School of Arts and Sciences Instructional Computing Development Fund and is freely available to Penn students and staff. Others who wish to use it must do so under a license.
If you are not affiliated with an institution that has a site license for Trees, you may download a demo of the Player for Trees for Windows [version 3.0.1]. The program will also run in the WINE environment under Linux or Mac OSX. The download includes a grammar tool useful in constructing trees for display in word processing documents and a MS Word file of instructions on how to use the program. The download file is in zip format and must be converted by "StuffIt Expander" or a similar program. If your Web browser is configured to use the conversion program as a "helper" application, the conversion will happen automatically.
The demo player version of the program will work with any grammar tool written for Trees 3 but does not permit the writing of new grammar tools. A sample of grammar tools that have been written at Penn for syntax courses is available here. The demo runs for 30 days after download. If you want to keep using Trees Player after that time or if you want to write new grammar tools, you must purchase the program. The cost for an individual user is:
The full version of the program comes with a built-in programming language Tree Talk, which allows users to write new grammar tools with rules of syntactic composition that they specify. These grammar tools are useful for creating homework exercises or exam problems in syntax courses and for demonstrating how syntactic analyses work. There is an accompanying manual that explains how to build these grammar tools.
Trees is available for purchase from the global internet reseller Kagi:or from Google Wallet: Multiple user site licenses are also available at higher cost for instructors who want to use the program for teaching purposes. These licenses include multiple copies of the full version of both the Windows and the Macintosh flavors of the program. The program will also run under Linux, using the WINE environment. For further information on the cost and conditions of a site license, click here.