The major pillar of Swedish role playing games, Drakar och Demoner (Dragons and Demons) was most certainly inspired by Dungeons & Dragons, but wasn't a translation, but an application of Basic Roleplaying.
The game has gone through a number of different editions and has changed during the years. The very first edition from 1982 was a mere translation of Basic Roleplaying and Magic World, the subsequent rewritings from 1984, 1985 and 1987 did change the rules a bit but was still the same basic system, thus these three are considered to be the same RPG.
The expansion module Drakar och Demoner Expert from 1985 was a revamp of the rules, a variant of the rules, but changed the system from percentile dice to a system using mostly only d20. Since these "Expert" rules was what most modules were written for before the 4th edition in 1991, it is considered as an RPG in its own right.
In 1991, for the fourth edition, the Expert rules were integrated in the base rules and a bit expanded, thus separating the system from Basic Roleplaying.
These editions all came without a campaign setting, but as new modules were released, an official campaign setting called Ereb Altor was gradually formed. It was sometimes accused of being unorganised, as a lot of different people wrote modules for it.
For the fifth edition in 1994 (and as Äventyrsspel turned into Target Games), a whole new campaign world was created - Chronopia, a slightly darker version than the typical 1980s heroic Ereb Altor. Although the rules were slightly tweaked to fit the new campaign, they remained virtually the same, and thus Expert, 4th edition and Chronopia are regarded to be the same RPG.
As Target Games got financial problems, Drakar och Demoner was licensed to Riotminds who created the sixth edition in 2000 and also a whole new campaign world: Trudvang, a campaign world that was much more inspired by Scandinavian folklore and fairy tales.
Riotminds' sixth edition was largely different from the earlier Drakar och Demoner and is thus considered a separate RPG. Riotminds edited this sixth edition of Drakar och Demoner slightly with some Expert rules in 2002, and a new edition in 2003 that contained some of these rules.
In 2006, a new version called "Drakar och Demoner Trudvang" was released with a major rules overhaul, probably the biggest since the creation of the game, where they got rid of basic traits and replaced it by "exceptional abilities" and the rest was skill-based. The campaign world was the same.