Thomas Charlton would like to clear up a few myths and misconceptions about his management style.

First, the one about his ripping a subordinate's door off its hinges in an office rage while chief executive officer of a Silicon Valley firm in the early 2000s.

"Every single door in the office came off except the CFO's." According to Charlton, he merely wanted to create an office atmosphere of openness.

What about the alleged use of a hammer to pry open a vacationing colleague's locked credenza at that same firm, Tidal Software Inc.?

"The hammer-to-the-credenza is an absolute truth." But, he says, he did it to get a critical sales file at the end of a crucial financial quarter.

Charlton now serves as CEO of Shunra Software Ltd., a software firm with offices in Israel, the United Kingdom and Sweden, that is moving its headquarters from New York to 1818 JFK Parkway in Center City this month. Charlton, on loan as CEO from major Shunra investor Insight Venture Partners, ordered the move after having spent nearly two years as a resident of Philadelphia's Rittenhouse Square.

He knows what it looks like - CEO doesn't want to commute, so he orders the whole company to move to him.

But the real reason, Charlton said, is cost.

"There's easily a 40 percent decrease in everything," from office space, to salaries, to housing for workers, he said.

Take hiring an inside sales rep, for instance: "In New York City, to get the bottom of the barrel, you have to give them at least $100,000."

In Philadelphia, he said, an ad for such a job recently netted 40 responses in 12 hours, even at a salary of $70,000.

Shunra expects revenue of about $20 million this year, with 100 employees worldwide, including about 40 here.

While not a computer engineer himself, Charlton can explain in detail the intricacies of Shunra's "network emulator" product. Consumers would never have any need for it, but there is a growing demand from large companies. A few clients include 3M Co., General Electric Co., Boeing Co. and General Motors Corp., among others.

A network emulator hooks up to a company's computer network and logs the flow of data, usage patterns of employees and customers, and information bottlenecks, to test for weak points.

It's an obscure but potentially lucrative niche of the business-software industry, and there are only a few major competitors, including Opnet Technologies Inc., of Bethesda, Md.

Charlton, now 40, gained notoriety for his hard-driving techniques after he engineered an audacious coup d'etat at Tidal Software in Mountain View, Calif. - persuading the board to install him as CEO - during the dot-com boom.

A 2001 cover story in Inc. magazine portrayed him as either a ruthless corporate climber or a relentless achiever who demanded that subordinates share his own full-throttle work ethic. Seventy-hour workweeks for employees under Charlton at Tidal Software were not uncommon.

The fact that he grew up as a Golden Gloves-level amateur boxer and still trained fiercely in his 30s did not help to soften the tough-guy image.

"About five minutes before I met him, I saw this article," said Bruce Eidsvik, cofounder of a Canadian voice-recognition software firm called VoiceGenie Technologies Inc.

Sometime after the Inc. article, Charlton had moved on to Insight Venture Partners, which sent him to take over as CEO at one of the companies it was invested in: the ailing VoiceGenie.

Like many tech enterprises, the engineering-minded founders struggled with the business side of their operation as it matured.

After reading the magazine, "I thought maybe it was time to get a new job," Eidsvik said.

But, he said, the profile blew the man out of proportion.

It was "a fairly significant misinterpretation."

"He's a demanding guy. . . . It was important to get results, but it was OK to have fun, too."

Turnover was low, Eidsvik said - after Charlton fired the bottom performers, mostly in sales.

"We knew what we needed to do, and he let us do it. . . . The whole management team bought into the results," he said.

The turnaround was dramatic enough to persuade Genesys Telecommunications Laboratories Inc., a unit of French telecom giant Alcatel, to acquire the company in April. Eidsvik now lives in Paris, where he heads VoiceGenie's Europe, Middle East and Africa operations.

Charlton, who stands a lean 6-foot-4 with immaculately gelled hair, indeed might evoke for insecure underlings Christian Bale's disturbingly driven character in the 2000 movie American Psycho.

Originally from Camp Hill, Pa., his boxer father taught Charlton and four other siblings to fight and to never surrender - in a fistfight or in life.

Naturally, Charlton is a Rocky Balboa fan. Has he ever run the Art Museum steps? "Of course, are you kidding?"

As for Shunra, Charlton seems to be bringing the intensity he brought to previous positions. He dictates that all potential hires must pass an entrance exam with a score of 90 or higher.

"In Canada, they almost revolted," he said of his charges at VoiceGenie when they learned of the testing requirement.

It is for the company's and their own good, he said.

"HP and Pepsi aren't particularly shy about dismissing small software companies" that fail to deliver, he said.

"Any company I run, it's either 'spotlights or headlights' - you're either a star or you're getting run over."

Any tire marks he may have left at Tidal Software seem to have been erased. There is no trace of his existence on Tidal's Web site, which catalogs news releases and company media mentions dating back to 2000. A spokeswoman for the company did not immediately return calls seeking comment.

Charlton's current bosses at Insight, though, seem confident to give him a long lead.

"The expertise, demeanor and professionalism he brings to every deal is exemplary," said Nikitas Koutoupes, a principal at Insight Venture.

As for the decision to move camp to Philadelphia, Koutoupes said: "We don't scrutinize those types of decisions, because we believe in him.

"He's earned carte blanche."

Paul Throldahl, vice president of sales for Realm Business Solutions, worked with Charlton at Tidal Software, when their competitors were juggernauts like International Business Machines Corp. and Computer Associates.

"When you work for a small company, you need to have that sense of urgency."

He said that Charlton was not a whip-wielder, but that passive types need not apply either.

"He hires really good people and allows them to run the route and get the mission done."