Link: http://www.bizjournals.com/triangle/stories/1998/12/14/story1.html

When I worked for James Martin Associates and Texas Instruments Software in the 1990's, we competed for a long time with Seer Technologies. Although it was never officially confirmed, rumor at the time was that their core product, Seer/HPS, was in fact a copy of IEF, created by a clandestine reverse-engineering exercise at CSFB, who were an early (and short-lived) licensee of IEF.
From about 1990 through to 1994, Seer represented significant competition for IEF, partly because IBM was a Seer distributor, and would aggressively pitch Seer/HPS in competition against IEF with its customer base and prospects. IBM at the time was pitching Seer mainly because it had no Model-Driven Development tool of its own; we had talked to them about IEF being part of their AD/Cycle initiative in 1989-90, but the talks fell through, possibly because IBM's licensing terms were way to onerous for TI to tolerate (for evidence about what happens when IBM gets to screw over licensees and partners, see The Fate Of OS/2).
After 1994, competion from Seer dissipated, and the competition became the new generation of visual development tools such as PowerBuilder and Visual Basic.
This article (from 1998) is a neat summary of how Seer rose, peaked and crashed back to the ground. By the way, the rumor that Sterling Software seriously looked at buying Seer is almost certainly true - I heard that rumor internally within my employer in 1997 after we were bought by Sterling Software.
I am currently working on a similar article looking at the rise and decline of the IEF division of Texas Instuments. A companion article is also in the works which expands on other articles about why CASE tools are currently seen as an industry failure.