Technology was late to come to the world of lawyers and law firms, long known for quill pens and steno pads. But now that it has arrived, it is spreading briskly.

"Within the past five years, technology in law firms has really, really advanced," said Randi Mayes, executive director of the International Legal Technology Association, an Austin, Texas, group that represents 1,700 US law firms and legal departments.

A primary driver of this evolution is the need for law firms to keep pace with the technology used by their corporate clients.

The explosion of electronic discovery has also forced law firms to become more tech-savvy.

And new federal statutes that require extensive financial reporting and electronic record-keeping, such as the Sarbanes-Oxley Act, have forced the rapid adoption of technology in the legal profession.

Technology has become critical to most industries, of course. But the legal profession resisted the age of technology much longer than many others.

"When I became a lawyer in 1990, the legal profession was a paper-and-pen business, and almost everything was done by typewriter and forms," said Alan Klevan, a Wellesley lawyer who chairs the Massachusetts Bar Association's law practice management section, which helps law firms use technology to enhance the practice of law.

Last month, the association hosted a legal technology expo in Needham that attracted several dozen technology firms that pitched their products to lawyers.

Now, however, the management of cases can be so complicated and time-consuming that technological assistance is critical. Software programs used by law firms handle receipts, billings, expenses, negotiating leases and insurance, personnel issues, time keeping, word processing, cost recovery, conflict checking, marketing, scanning, docketing, and data storage. Special tax-reporting software exists for trusts and estates departments, and financial software aids bankruptcy groups.

During electronic discovery, countless documents, files, phone records, and electronic correspondence are mined in civil litigation. Software can be used to comb through e-mail systems and identify key information, sparing lawyers or legal assistants the task of reading through hundreds or even thousands of e-mails in search of important data.

"Before, we'd get boxes of paper, and paralegals would go box by box by box, coding and figuring out what was important on each page," said Henry Chace, chief information officer at the Boston law firm Burns & Levinson, whose 125 lawyers collectively use about 70 software applications. "Now we just scan those documents and use algorithms to determine what's important or not."

As law firms increasingly become global operations, their multiple offices worldwide must also have time-and-billing software that works with multiple currencies.

At large firms, conflict checking, to ensure that the firm does not represent a client whose interests clash with the interests of another potential client, is also done electronically.

"If you're opening a matter in San Francisco, you have to find out if you have any conflicts with the Tokyo, New York, Singapore, and London offices, and you can't start billing till you know," said Chace, a former president of the International Legal Technology Association. Without software that runs such checks, the process would be unmanageable, he said.

Litigators tend to be at the cutting edge of technological advances because they rely on high-tech software to manage their cases and impress juries during trials.

But other types of lawyers remain well behind the curve. Many real estate lawyers, for example, still make in-person visits to courthouses and registries of deeds to file paper documents.

But that, too, is changing.

"Real estate lawyers used to have to trudge to the registry with a check and documents in hand," said Paul Roth, regional sales director for Simplifile, a system that enables real estate documents to be filed electronically. "Now they just have to sign on [to a computer] and send them in."

Simplifile sells its product in 20 states, but in Massachusetts the only registries of deeds that allow electronic filing so far are in Lowell, Springfield, and Plymouth, Roth said.

Despite these technological advances, "I still drag a lot of solo practitioners kicking and screaming into the technological age," Roth said.

"Most of them say they're fine the way they are, and they really want to leave it to the next generation to change."