Originally called "Outside In" and released by the Software Compatibility Corporation, which was bought out by Inso
Outside In was a basic viewer program with a collection of optimized filter plugins which gave the ability to view a large number of common file formats in a state resembling their intended appearance. The program had the ability to automatically detect the format of the file, ostensibly by filename extension but in some cases also by file headers. The original program also included a well-done filesystem browser.
This program was repackaged, slightly updated, and slightly more optimized. A trimmed down version was named Quick View and shipped with most versions of Windows 95. The "Quick View" option on the right-click drop-down menu of many types of files in Windows 95 started this program.
A more advanced version of this program (mainly just with a larger collection of filters) was called Quick View Plus and is still commercially available from Inso. The core technology, still called Outside In, is also available as an integratable software module and as a web server extension.