As I recall from my days as a Déjà Vu user, projects could have multiple target languages, but without the Workgroup version, collaboration was made difficult by restrictions on the bilingual files ("external views"). I don't know if this is still an issue in DVX3, because the uncertain future of Atril makes me reluctant to invest much study time in that tool.
memoQ does not restrict the languages one uses, but creating a project with multiple target languages requires the Project Manager edition. Kilgray doesn't talk much about this edition of memoQ and usually tries to link it to a server license sale (or a memoQ cloud subscription); if you look on the Kilgray web site, you will find very little information. I think the license typically costs about €1500, with €300 (20%) annually for maintenance upgrades and support. Quite a bargain, actually, and with the PM version one also gets access to another well-kept secret: the memoQ client API, which can be used to automate or simplify a number of project management processes. And of course with the PM edition one can create convenient "handoff packages", which provide convenient resource bundles for collaboration with other memoQ users with compatible versions of the translation environment tool.
But the memoQ PM edition is total overkill for someone who typically needs only individual language pairs for work and is faced only rarely with the need to manage multiple target languages from a source language. If there are just a few languages involved, it's probably not a big deal for someone with the memoQ Translator Pro edition to create several projects (one for each target language needed). There is, however, another option worth considering in some cases: using the Translator Pro edition to manage a multilingual project created with the PM edition.
Using a project with multiple target languages in the Translator Pro edition requires, of course, that the original project be created by someone with the Project Manager edition. And the sophisticated functions for reporting, package creation, etc. are not available when the project is open in the Translator Pro edition. But translation memories, termbases, LiveDocs and other resources can in fact be managed for multiple target languages in the project. The work can be reviewed or prepared for external proofreading, target files can be created in all the languages, and a number of other simple management tasks can be performed. In many cases this may be enough.