Software with same name as other software but in different market

When you register a trademark, you have to pick one or more classes. There are up to 45 different classes from Chemicals to Telecommunications.

If a trademark is not taken in the class that refer to your industry, you have to right to use it and to register it. But that's not that easy...

... you can't register common words easily, you have to prove you will use it in business (or are using it in business since months, years, ...) and anyone can ask your mark to be invalidated if they can prove they used it before you (you must register it in good faith).

You will have to hire a specialized lawyer, this is not a simple subject.

To get an idea, go here, and search for your product names.

It probably apply only to non registered trade marks or to words that are in dictionary. "Made" words is probably difficult to use even in other markets. For example eclipse is dictionary word (you know something about the sun :).

From a non-legal perspective, if the other product aren't well known then it might be okay, but it's still probably better to use something at least slightly different.

If it is well known or you suspect they might become well known (more so than your own product) then it could cause confusion among your users, like when they do a Google search for instance, yours better be in the #1 spot for your own product name.

Even if yours will become more well known, you're also possibly going to hurt their branding even though they're not a competitor to you. This may or may not matter to you, but it's something to think about whether you'd like someone else doing the same to you. (Or maybe they do get big and you're the one who's brand is hurting)