It’s shades of 1999 in Silicon Valley.

“This is the busiest things have been since then,” said Gordon Dav­idson, chairman of Mountain View, Calif.-based Fenwick & West. “We’re having a little déjà vu. We started to see tech come back a year ago, and it’s now back to a high level of activity.”

While social media companies like Facebook Inc. and Twitter Inc. have been grabbing the headlines, more traditional Silicon Valley industries including clean technology, semiconductors and software have also bounced back, Davidson said.

Initial public offerings — all but ­moribund during 2008 and much of 2009 — have ramped up. Fenwick worked on four IPOs during the past year and now is working on another three — compared with two during the previous year. “We’ve got more in the pipeline, and our peers are saying the same thing,” Davidson said.

It’s not just corporate attorneys who are keeping busy. Fenwick’s patent litigators are the busiest they have ever been, Davidson said, and securities litigation has emerged from a two-year hibernation.

Silicon Valley’s rebound has led to more competition among local firms to snag lateral talent — a trend Davidson began noting several months ago. Fenwick has added eight lateral associates since last summer.