Jeff Taylor contracted Christopher Caldwell of Net Daemons Associates.......

Jeff Taylor contracted Christopher Caldwell of Net Daemons Associates to develop a facility in an NDA lab on a Sun Microsystems Sparc 5 where job seekers could search a job database with a web browser. The machine was moved to sit under a router in a phone closet in Adion (a human resources company owned by Taylor) when the site went live in April 1994.

Initially, the site was populated with job descriptions from the newspaper segment of Adion's business with the permissions of the companies advertising the jobs.

Later in 1994, The Monster Board issued a press release that was picked up and provided needed exposure to drive people to the web site. Monster was the first public job search on the Internet; first public resume database in the world and the first to have job search agents or job alerts.

When TMP acquired Adion, the site was moved into BBN Planet's web hosting facility where it grew from 3 SPARC-1000s to become the centerpiece of the globally distributed network it is today.

TMP went public in December 1996, with its shares traded on Nasdaq under the symbol “TMPW”. In 1998, TMP acquisitions expanded the Recruitment Advertising network. TMP became one of the largest recruitment advertising agencies in the world.

In June 1998, The Monster Board moved its corporate headquarters out of a small office above a Chinese restaurant in downtown Framingham, Massachusetts to an old textile mill in Maynard, Massachusetts that formerly housed Digital Equipment Corporation.

In January 1999, The Monster Board became known as Monster.com after merging with Online Career Center, another of TMP Worldwide's properties. The first post-merger president of the new Monster.com business was Bill Warren, the founder of Online Career Center. Bill Warren received the 1997 Employment Management Association's prestigious Pericles Pro Meritus Award, an honor presented by EMA/SHRM in recognition of being the founder of online recruiting on the Internet.

In November 2000, seeking capture the entry-level job market, Monster acquired JOBTRAK, which at the time had partnerships with more than 1,500 college and university career centers. JOBTRAK was founded in 1987 by Connie Ramberg, Ken Ramberg and David Franey. Monster rebranded JOBTRAK as MonsterTRAK and continues to operate the site to target college students and alumni seeking jobs and career advice.

Recognizing that job hunting often leads to relocation, Monster launched Monstermoving.com in 2000 to provide consumers with the comprehensive resources necessary for a successful move.

TMP Worldwide was added to S&P 500 Index in 2001. TMP Worldwide changed its corporate name to Monster Worldwide, Inc. and began trading under the new Nasdaq ticker symbol "MNST" in 2003.

Monster.com advertised on the Super Bowl starting in 1999 and every year through Super Bowl XXXVIII. Monster's first-ever Super Bowl ad, "When I Grow Up," (created by Mullen) asking job seekers, "What did you want to be?" It is the only commercial named to Time magazine's list of the "Best Television of 1999." As the official online career management services sponsor of the 2002 Olympic Winter Games and 2002 U.S. Olympic Team, Monster had a strong presence at the 2002 Olympic Winter Games in Salt Lake City.

In April 2002 Monster purchased the Jobs.com URL and Trademark for $800,000. Then Founder and Chairman Jeff Taylor was quoted as saying "Jobs.com is a desirable URL."

In August 2005, founder Jeff Taylor left Monster to create Eons.com.

In May 2007[2] Monster launched their first (NA and EU) Mobile services offering Mobile job search and career advice.

In July 2008[3] Monster acquired Trovix, a semantic job search engine, for USD $72.5 million. Monster has indicated that it plans to replace their job search and candidate matching with Trovix's technology.