Wow, with over 13,000 posts to your name, I would have hoped you could perform the simplest of researches. One click found the fact that it is a 501(c)3 corporation. (under support us)
Then a quick Google tells us that type of corporation is a charity. Here is the Wiki info:
In the United States a charitable organization is an organization that is organized and operated for purposes that are beneficial to the public interest,[18] however a distinction is made between types of charitable organizations.
Every U.S. and foreign charity that qualifies as tax-exempt under Section 501(c)(3) of the Internal Revenue Code is considered a "private foundation" unless it demonstrates to the IRS that it falls into another category. In a general sense, any organization that is not a private foundation (i.e. it qualifies as something else) is usually a public charity as described in Section 509(a) of the Internal Revenue Code.[19]
In addition, a private foundation usually derives its principal fund from an individual, family, corporation, or some other single source and is more often than not a grantmaker and does not solicit funds from the public. In contrast, a foundation or public charity generally receives grants from individuals, government, and private foundations and although some public charities engage in grantmaking activities, most conduct direct service or other tax-exempt activities.
This leads to another distinction: Foundations that are generally grantmakers (i.e. they use their endowment to make grants to other organizations, which in turn carry out the goals of the foundation indirectly) are usually referred to as "grantmaker" or "non-operating" foundations. These of course tend to be private foundations. Some private foundations however, (and most public charities) use their received funds to directly engage in service activities themselves and achieve their goals "personally," so-to-speak.
Examples of a non-operating private foundation would be the Rockefeller Foundation and the Bill & Melinda Gates Foundation.
Examples of operating foundations or public charities include the Elizabeth Glaser Pediatric AIDS Foundation, American Cancer Society, Inc., and the World Wildlife Fund.
The requirements and procedures for forming charitable organizations vary from state to state, as do the registration and filing requirements for charitable organizations that conduct charitable activities or solicit charitable contributions.[20] So effectively in practice the detailed definition of charitable organization is determined by the requirements of state law of the state in which the charitable organization operates, and the requirements for federal tax relief set by the IRS.
I'll say you are getting smarter though, at least you didn't ask if the FORUM is a charity.