OPNET let network engineers crash a network without breaking anything. Its software built a model of a company's network and its applications, then ran them forward to show where traffic would jam. Phone carriers, internet providers and large companies used it to plan upgrades and chase slowdowns. By August 2000 it had licensed its software to more than 600 organizations, and the company in Washington, D.C., was ready for Nasdaq.

MIL 3 and a Simulator

Marc Cohen and Alain Cohen started the company as MIL 3 in Maryland in 1986. Marc was chief executive and Alain ran the technology. Their product, OPNET, used predictive simulation to test network designs under many conditions. The company changed its name to OPNET Technologies in February 2000. Revenue had grown to $19.2 million in its latest fiscal year, and it had been profitable for most of its history.

Netted by Riverbed

OPNET priced 4 million shares at $13 on August 1, 2000, and listed on Nasdaq as OPNT. It came through the dot-com crash and grew into tools for watching how applications perform across a network. In late 2012 Riverbed Technology bought OPNET through a tender offer. Each OPNET share received $36.55 in cash plus 0.2774 of a Riverbed share. The stock left Nasdaq in December 2012.

Cover: Youth with Fish Net, Shibata Zeshin. Art Institute of Chicago, public domain. Chosen for a youth with a fishing net (the network).