Borland Turbo Basic

Turbo BASIC began as BASIC/Z, created by Robert "Bob" Zale as the first interactive compiler on CP/M, and was brought to MS‑DOS when Borland purchased it in 1987. Unlike interpreters such as GWBASIC, Turbo BASIC compiled programs into executables and object (.OBJ) files, removing the 64 KB .BAS size restriction and allowing much larger programs limited only by available memory. It shipped with an integrated development environment that let developers edit, set compile and memory options, run in memory, or produce .EXE files - features that positioned it as a professional tool compared with the common edit-and-run workflows of the era. Borland released versions 1.0 and a bug‑fix 1.1; the language was roughly 90% compatible with GWBASIC source (with a specific SAVE "name",A requirement for ASCII files).

In 1987 Borland augmented Turbo BASIC with three paid Turbo Toolboxes: a Database Toolbox supporting long integer record numbers (enabling databases of over two billion records), B+ tree indexing, and imports from ASCII, dBASE and Reflex; an Editor Toolbox offering RAM‑based multiwindow and pull‑down menu editors; and a Telecom Toolbox providing asynchronous communications routines, port control and screen handling. Each toolbox retailed around $99.95. At its peak Borland occupied an extravagant Scotts Valley campus built in 1993 - seven buildings, 444,000 sq ft and extensive amenities - later sold in 2013 for about one‑tenth of its original $120M cost.