What are the differences between M.Sc, M.Tech and M.Eng.? Based on this other question where the OP asks whether or not a second Masters degree is possible, I realized that I am not sure what the difference is between Master of Science and Master of Technology. 

I have graduated from a Swedish university and after 5 years of studies (Bologna process) I got my undergrad (kandidat) and masters (examen) together as it is very common here. I double checked my diploma now and even though I have graduated from the technical faculty and an engineering program, I am given a Master of Science. I believe there is no Master of Technology degree in Sweden, so I am not sure what it means. To make the matters worse, I stumbled upon another similar degree, Master of Engineering.

I would really appreciate some insight into the differences of these degrees, and whether or not they would be considered interchangeable abroad (read: outside Europe).
There are some differences, especially in the concept of the programs M.Eng./M.Tech. and M.Sc (and M.A. obviously too).

From my experience, and Wikipedia states this also, the M.Eng./M.Tech. degrees are rather given by Universities of Applied Sciences (at least in Germany, Canada, Finland etc,) and seldomly by Universities focusing on research. Any program that is research oriented will thus very likely give M.Sc. degrees.
The M.Eng. is even given as an undergraduate Master in the UK (see the Wikipedia Link) that gets granted immediately (without a bachelors in between).

For the career of a graduate, the title itself is not too important as aeismail mentioned, since any employer will have a look at what's inside (= the student track record).

Because there are so many slightly different programs, especially in computer/information engineering/technology/sciences I am not sure where universities draw the line regarding the "not granting a 2nd masters degree in the same field/area/discipline" policy.