https://ell.stackexchange.com/questions/17108/what-is-the-tm-of-do-the-right-thingtm
The Right Thing (or sometimes The Right Thing) is an old computing term (see the Jargon File entry for "Right Thing") whose meaning has somewhat changed over the years but (contrary to the Jargon File definition) in current use it often means that having two ways to go about doing something, reasonable people would agree that there is one correct way, hence "The Right Thing".
"TM" (often used as the single unicode symbol "™" or with parenthesis "(tm)"), is the Trademark Registration sign, which is used to convey that a party owns the specified phrase (at least in a usage category) by having it registered with a government trademark office.
Obviously "The Right Thing" in this case is not an actual registered trademark, but the use of the term was so common, with the capitalization - which is also how one uses trademarked names in technical documents, specifically for terms that normal people would have thought are standard English terms but some companies have managed to trademark, e.g. Windows™ - that many people have started adding "(tm)" after "Right Thing" as a half-joke and for extra emphasis.
While the use of "The Right Thing" is very early, the addition of the "(tm)" or trademark symbol is from the late 1990s, in usenet and open source software mailing lists.
In regards to mplungjan's answer, I don't believe this is a play on Coca Cola's trademarked phrase - this is 100% internal computer industry play on words, or play on how trademark was used to steal basic terms from the domain of the English language.
Jargon File, Eric S. Raymond, do the Right Thing™
