h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

There are thousands of people who were once part of the Church of Scientology, but for any of numerous reasons broke off, but continued to utilize the "Tech". Several of these people were senior members. Over time this phenomenon became known as the "Free-zone". There are several different camps in the Free-zone, usually grouped around a particular figure or followers of the same, as well as highly experimental groups who utilize some aspect or another of the teachings of Scientology. Most Free-zoners highly admire L. Ron Hubbard, though there are some who believe that Hubbard actually borrowed or stole from other sources.

In addition to Free-Zone Scientologists their are groups that used some Scientology material:

The Process Church

EST

There are also individuals who worked with some Scientology material, often is creative and disturbing ways; William S Burroughs for example.

The existence of the Free Zone should act as further confirmation to skeptics of Scientology's claims, because it tells us the same people that leave the church with allegations of corruption are still nevertheless convinced as to the efficacy of the things they have learned.