Development was put on hiatus in 1994 after slow sales on the Windows platform, and officially ended in April 1996 after Lotus was purchased by IBM.

Although not a commercial success in comparison to mainstream products like Lotus 1-2-3 or Microsoft Excel, Improv found a strong following in certain niche markets, notably financial modeling.

It was very influential within these special markets, and spawned a number of clones on different platforms, notably Lighthouse Design's Quantrix.

[2] Teaching the use of spreadsheet modelling was common in business schools, often using chalkboards marked up with a layout similar to the paper versions.

When Ben Rosen of Morgan Stanley saw the program, he wrote that "VisiCalc might be the software tail that wagged the computer industry dog.

His version, Lotus 1-2-3, would go on to be an even greater success than VisiCalc, in no small part due to the fact that it ran on, and was tuned for, the new IBM PC.

Completed spreadsheets were easy to use, but many users found it difficult to imagine what the sheet needed to look like in order to get started creating it.

Yet in every case, the existing spreadsheet programs required the user to type all of these items into the same (typically single) sheet's cells.

At the same time, the new product would allow users to group data "by purpose", giving it a name instead of referring to it by its position in the sheet.

Salas demonstrated that this separation meant that a number of common tasks that required lengthy calculations on existing spreadsheets could be handled almost for free simply by changing the view.

Additionally, NeXT's Interface Builder let the team experiment with different UIs at a rate that was not possible on other platforms, and the system evolved rapidly during this period.

This led to one of Improv's most noted features, the category "tiles", icons that allowed output sheets to be re-arranged in seconds.

Blumberg remained on-call to help with technical issues, which became serious as NeXT was in the process of releasing NeXTSTEP 2.0, the first major update to the system.

The program was an immediate hit, receiving praise and excellent reviews from major computer publications,[8] and, unusually, mainstream business magazines as well.

The APIs and programming language for NeXTSTEP were so different from Windows and Macintosh system software that porting was very difficult.

Like the NeXT release, the Windows version also garnered critical praise,[13][14] with Byte magazine noting its "usability is outstanding".

[17] The project was left in limbo until April 1996 when the product was officially killed, shortly after IBM purchased Lotus.

[18] Improv's disappointing sales and eventual cancellation on the PC platform has been used as a case study in numerous post-failure analyses of the software market.

Among the favored explanations are the fact that, unlike the release on NeXT, the Windows version faced strong internal resistance from 1-2-3, and corporate immune response became an issue.

Other explanations include the fact that Microsoft Excel was being offered as part of the Office bundle at marginal rates that were tiny in comparison, as well as several mis-steps during introduction, like the lack of a macro language or undo.

Joel Spolsky blames it on the design itself, claiming it was too perfectly aimed at a specific market and lacked the generality that Excel featured.