A: Accidental Centaurs is the story of Alex and Sam, scientists who were working on an experimental teleporter when it malfunctioned and opened a vortex into another dimension. There, they find they have been transformed into centaurs, as Homo sapiens can not exist due to the laws of physics, chemistry and biology of that universe. They also discover Lenny, a wisecracking djinn that has been assigned by the rulers of this new universe to be their guide and protector.
A: The strip originally launched on January 16, 2002. That original continuity ran until 2011, when it was rebooted and "reimagined". The old continuity was deprecated and is now only available in a print book. The rebooted storyline is the current and official one (and according to the cartoonist, far, far superior).
A: In February 2016, the cartoonist announced that Accidental Centaurs was going on hiatus. The reason for this increasing pressure from other projects and questions about the financial viability of the property. While the strip is on hiatus, it is not dead. The cartoonist has stated that he fully intends to revisit Accidental Centaurs in the future. Plus, there's also other, related activities going on.
A: Speaking of related activities…
"Plain Brown Wrapper", "Naughty Bits" and "Alternate Centaurs" are brand names for adult, not-safe-for-work material that is related to the Accidental Centaurs universe. They can be classified as "erotica" that uses the Accidental Centaurs characters and settings. Stories branded as "Alternate Centaurs" are not a part of the mainstream Accidental Centaurs canon. "Plain Brown Wrapper" (a Monty Python reference) refers to stories distributed in comic book format. "Naughty Bits" (another Python reference) is used to brand collections of this material.