Everbridge Inc., an emergency communications software seller that helped city officials coordinate police and firefighters during the Marathon bombings, raised $90 million for itself and some existing shareholders Thursday as it priced its initial public offering.

The Burlington company sold 6.25 million shares at $12 each, in the middle of the $11 to $13 per share range the company disclosed in previous regulatory filings. Previous investors sold another 1.25 million shares, Everbridge said.

Everbridge is the second Massachusetts-based technology company to complete an IPO this year. Maynard’s Acacia Communications Inc., which makes telecommunications equipment, raised $103.5 million in May.

Only one Massachusetts tech company went public last year: Rapid7 Inc., a Boston cybersecurity software developer. That was part of a slow year nationally for IPOs. Investment adviser Renaissance Capital called 2015 “a disappointment,’’ with 170 deals raising just $30 billion, the lowest in six years.

Everbridge is not yet profitable, despite growing revenue. The company came close to breaking even in 2014, losing $623,000 on sales of $42.4 million. But its spending spiked in 2015, when Everbridge lost $10.8 million on sales of $58.7 million.

Everbridge was founded in the ­aftermath of 9/11, when the catastrophic terrorist attacks highlighted problems with some government ­emergency-communications systems.

Public and private customers use Everbridge’s software to send alerts to phones, e-mail addresses, pagers, and electronic road signs. Everbridge said its clients include eight of the 10 ­largest US investment banks and 24 of North America’s busiest airports.

Everbridge messages can be routine reminders, like a nudge to move your car for street sweeping. But the system is specifically designed to ­function during emergencies, with the ability to route evacuation notices or requests for aid over land-line phone and wireless Internet networks when cellular towers are jammed with calls.

Everbridge’s system can be used to account for far-flung employees, ­asking them to respond by pressing a button if they are safe. Its alerts also can be targeted by location, telling people in one building to evacuate while urging their co-workers in ­another location to stay put.

Sony Pictures, for example, used Everbridge to communicate with thousands of employees after a ­massive hacking attack in 2014 ­crippled the movie studio’s IT networks. The city of Santa Clara, Calif., used Everbridge earlier this year to send weather forecasts, traffic alerts, and safety messages to people visiting for the Super Bowl.

ABS Ventures, a Waltham-based venture capital firm, was Everbridge’s largest shareholder before the IPO, with 31 percent of the company’s stock. Everbridge chief executive ­Jaime Ellertson owned nearly 14 ­percent of the company, while cofounder and former chief executive Cinta Putra owned about 11 percent, regulatory filings showed.

Everbridge shares are expected to begin trading on Nasdaq on Friday under the ticker symbol EVBG.

Curt Woodward can be reached at curt.woodward@globe.com. Follow him on Twitter @curtwoodward.