This isn't about a game, but a tool related to games, so I hope that's OK.

I've recently had an idea about a software tool that would provide a new way to look at one's Steam profile.

I'm wondering if there are legal issues to creating such a tool. Is this sort of thing common? Is it totally out of the question, perfectly legitimate, or questionable? I really have no idea, and I've never even considered selling software that isn't a game (my company is called Cheese and Bacon Games!) but if it is an OK thing, it would not take long to create it and try it out (famous last words...)

It's hard without knowing the details, but in general you are free to reverse engineer things and do what you like with the data.

That's great news, thank you!

The Apple/Palm thing sounds like a funny story, heh.

What about naming? For instance, could I call it something like "Steam Sorting Thingy"? That seems like it would be problematic, but if so, how would anyone ever know what it was?

Seeing that Valve post the Steam Web API online, I don't think they'd be antagonistic towards you providing "a new way to look at one's Steam profile."

See here for the community-sourced information (also hosted on Valve-controlled web servers).

You have seen things like Steam Gauge, right? Apparently I have $2278.59 worth of games, that take a total of 468.14 GB, and that have been played for 2605.9 hours.

I've never used Steam Gauge specifically before, but there are dozens of sites like that. Never give them your passwords, obviously, but most just ask for your Steam account name, which is already public.

Oh wow, I did not know that API existed, thanks! Heh, I've just been gathering all the info I need from their site. I.e., you give it a Steam username, and it builds a list of your games from the profile page's HTML, then it looks at each game's store page for more info on it. It actually works really well but this might simplify some things :-)

So the only real issue is with the name. It looks like Steam Gauge just has a disclaimer on the page saying that Steam is Valve's thing. Is that enough, or should I be safer/more paranoid and not have Steam anywhere in my program's name? Bear in mind I am thinking of selling it (on mobile, maybe), in case that is relevant.

Also, the number of hours you've played Awesomenauts makes me sad, Servant of the Lord, it's a great game! :-(

Valve is very community-friendly. Legally, using the name Steam would be a no-go, but Valve doesn't go lawsuit crazy - they have a reputation to protect with their fanbase.
When a bunch of modders were making a remake of Halflife 1 with the Source engine, Valve encouraged it. When they called it "Black Mesa Source", Valve politely sent them an email asking them not to use the name "Source", so Valve can use it to mark official Valve products (Day of Defeat: Source, Halflife: Source, CounterStrike: Source, etc...), and suggested just naming it "Black Mesa"... but let them continue to use their "blackmesasource.com" domain name so they wouldn't have to spend $10 on another domain.

I think the disclaimer would be fine - but shoot Valve's community management team an email, explain your project, and ask them if "Bob's Steam Profile Tool" is an acceptable name to use.

Uh, I'm not sure about you commercially selling the product, but you can email them about that too. Maybe make it donation-based, and ask Valve if they're cool with that.

Re: Awesomenauts

I got it in a bundle (one of the Humble Indie Bundles, iirc) only a month ago, so I've never played it.

Uh, I'm not sure about you commercially selling the product, but you can email them about that too.

Don't forget Steam Greenlight also does programs/tools as well games as one possible avenue.

Thanks a ton for all this advice, guys. It all actually sounds less scary than I expected. I'll definitely try to get in touch with Valve and just ask how they'd feel about it. I think I might make it even if they don't want it sold, because I think it could be useful to people. But I'd sure not mind making some money off of it, haha! Donations is a cool idea, that might be a good way to go.

I really only had plans for a mobile version, but my prototype is a little C++ Windows program so I could probably do a desktop version if I wanted.