It really depends who you ask.
Most promoters and detractors of NESARA agree that it is an acronym for a law, standing for “National Economic Stabilization and Recovery Act” or some variation.

According to The NESARA Institute, NESARA was originally created several years ago as a legislative proposal by Dr. Harvey Barnard, dealing primarily with monetary and fiscal reform. He mailed copies of the proposed bill to Congress, but it was never taken any further than that. The points of the original bill can be seen here.

Over time NESARA has morphed into something resembling a religious movement.

Sometime around 2001, Shaini Goodwin, A woman from Shelton, Washington began publishing regular reports on the internet under the pseudonym "Dove of Oneness." The reports claimed that NESARA has already been passed by Congress in secret, was signed into law by Bill Clinton, and placed under gag order by the Supreme Court. According to her, The NESARA Institute is a Bush-supported disinformation site designed to confuse people about NESARA, and what she calls “The True NESARA Law” has a scope much wider then the version proposed by The NESARA Institute. Goodwin has claimed that contacts within the CIA, FBI, and Congress are among her sources.

Goodwin is also a frequent guest on radio programs where she discusses NESARA, but never makes public appearances or reveals her true identity. Her identity remained a secret to her readers, up until July of 2004, when it was revealed by a scathing article published in The Tacoma Tribune. Her updates on the status of NESARA promise immense wealth to believers, as well as the resignation of Bush, Cheney, and all of Congress, but that's just the beginning.

For the past few years, Sheldan Nidle, head of The Planetary Activation Organization, has been discussing NESARA in the context of his prophesy of mass UFO landings and contact with alien civilizations. NESARA makes an occasional appearance on his website in his weekly update (which he claims is communicated to him directly from The Galactic Federation via a brain implant), but is featured more prominently in his seminars, such as "Sheldan Nidle and the Galactic Federation Present: Humanity’s Future: Galactic Contact and N.E.S.A.R.A." Several others such as Jennifer Lee and Patrick Bellringer have also been publishing independent reports on the NESARA status.

These sources do not always agree with each other on specifics, but there is a general consensus among believers that NESARA promises forgiveness of all debt, elimination of the IRS, world peace, unity with our space brethren, the disbandment of the current government and—some believers say—its replacement with religious deities, with Jesus Christ at the helm.

The film Waiting For NESARA focuses on one particular group of NESARA true believers out of Salt Lake City, Utah—and how they have been influenced by the NESARA phenomenon. We hope it brings up questions about faith, desperation, poverty, hope, money and debt in today's America, and how a new religion is born.

A current Google search brings up over 50,000 hits worldwide. (note: As of February 2006, this number has grown to between 170,000 and 205,000.)

NESARA CRASH-COURSE:
Wikipedia sums it up.

ABOUT DOVE OF ONENESS:
COLLECTED ARTICLES IN THE NEWS TRIBUNE (TACOMA,WASHINGTON)

KEY NESARA SITES:
Read Dove of O's Weekly reports (Published Mon mornings, sometimes Sun nights)

Sheldan Nidle's weekly updates (click and scroll to bottom for newest update.)

Planetary Activation Organization (Main website of Sheldan Nidle)

Message from Sheldan's Wife

www.fourwinds10.com (Patrick Bellringer’s site)

www.yesnesara.com (Jennifer Lee’s site)

SCAM INVESTIGATION:
Quatloos' NESARA page

Quatloos' Dove/NESARA message board

PHOTOS FROM VARIOUS NESARA GATHERINGS/DEMONSTRATIONS:
Dove's supporters page

Google image search on NESARA