Smalltalk is an object-oriented programming language and associated development environments. Smalltalk was originally released in the 1980s and strongly influenced modern GUIs and Java. It has experienced continuous development throughout the decades, allowing it to become a mission-critical and reliable technology for developing, deploying, and managing high-performance business objects. The power and ease of development and debugging in Smalltalk make it a natural fit for enterprise applications.
The GemStone/S server implements the ANSI Smalltalk environment, so programming in GemStone Smalltalk is similar to programming in other client Smalltalks. Code that is written for the commercial Smalltalk language implementations VisualWorks Smalltalk and VAST (VA Smalltalk) can easily be ported to GemStone.
The GsDevKit for GemStone/S 64 Bit environment provides compatibility with the open-source Pharo and Squeak Smalltalk programming environments.
GemTalk Systems is deeply committed to Smalltalk technology and the Smalltalk development community, and sponsors and attends Smalltalk conferences around the world.
Resources on Smalltalk
The ANSI Smalltalk Standard can be purchased here, or the draft version (similar technical contents, with additional comments) can be read for free online here.
To illustrate the history of the Smalltalk language implementations, see this diagram: The history of Smalltalk.
Much of the content on this Smalltalk 101 blog post is outdated, but there are some valuable links on Smalltalk, OO design, and the history of Smalltalk.