Wikipedia
GLPro is a multimedia authoring application for MS-DOS and Microsoft Windows. GLPro is a contraction of Graphics Language Professional, and was written by John Bridges. GLPro was originally a MS-DOS program released in 1995, written as successor to GRASP, also written by Bridges and marketed by Paul Mace Software from 1986 until 1994. Windows support in GLPro was released in the summer of 1996.
Unlike competing technologies such as Macromedia Director, GLPro takes a very minimalist approach, providing an extensive scripting language rather than a lot of WYSIWYG tools within a Graphical User Interface. Everything is accomplished by writing code using its BASIC-like syntax. The scripting language is not object oriented, and as a result consists of a very large number of specialised commands. The programmer is not able to create new classes or extend the language. It has been criticised for its syntactical inconsistency, steep learning curve, and the fact that it does not deliver a cross-platform multimedia solution. Despite this it has been enthusiastically received by numbers of users, many dating back to the early GRASP under MS-DOS days.
An unusual design philosophy behind GLPro is that it does not rely on external OS services to handle many media types, such as MP3 audio, MPEG video, etc. Instead it contains its own player code. The thinking is that by avoiding OS services for these tasks, the end user is spared the problem of needing to install additional components before being able to run a multimedia title on their machine - it is intended to "just work". Although an advantage for some standalone projects, this philosophy suffered from an inability to keep up with new media developments.
GLPro was moved into a separate company, GMedia, in early 2000, which closed their doors in February 2001 just as the native Macintosh and Linux support was entering public beta testing. Bridges is no longer involved in its development, and as of February 2002 is developing a new multimedia authoring system called AfterGRASP designed to be backwards compatible with GLPro with less emphasis on built-in media playback support.
GLPro is currently owned by Comlet Technologies, LLC. and is one of the primary languages used in its Comlets Message System product.