On October 26th, 2018 I purchased the software assets of Full Moon Software. Full Moon Software used to be known as Crescent Software. They produced a line of excellent development libraries for MS-DOS. The supported environments were QuickBASIC 4.x, Microsoft Professional Development System v7.x, and Visual Basic for DOS.
The idea behind obtaining these products was to release them to the public domain to ensure that people could still access these things in the future. While most developers will have no use for these products in a modern develoment environment, they still have value as an example of "how it was done" back in the heyday of x86 DOS development.
The software in this repository hasn't been modified from how I received it from Ethan Winer, the original author. While all the source files carry some kind of Copyright notice, the software is now in the public domain.
The original distribution disk files and documentation are available here:
http://annex.retroarchive.org/crescent/index.html
About Crescent Software: After 20 years as a professional recording engineer and musician, Ethan Winer founded Crescent Software in 1986, quickly building it to become the leading provider of add-on products for use with Microsoft compiled BASIC for DOS. During that time Ethan wrote numerous articles about DOS BASIC and assembly language for all of the major programming magazines, and also served as a contributing editor for PC Magazine. Ethan also received Microsoft's MVP award every year since 1996 for his assistance in the Microsoft BASIC programming newsgroups. In 1992 Ethan sold Crescent to his partner Don Malin, and retired in order to pursue his musical interests.
Here's the QB Plus product description from the manual:
QB Plus is a collection of software accessories developed especially for the QuickBASIC programmer. QB Plus extends the QuickBASIC programming environment by loading with it and remaining two keystrokes away while editing the QuickBASIC program in memory.
Provided with QB Plus are accessories to view the contents of memory; to record and playback keystrokes; to create executable programs using any of the compiler and linker options; debug them using an external debugger; and profile the execution of QuickBASIC programs to identify bottlenecks. Besides these built-in tools, the BASIC programmer can readily access other programs from within QB Plus.
QB Plus is designed to work with QuickBASIC 4.5; and the Basic Professional Development System versions 7.0 and 7.1.