Let's see :

Cyan Worlds catalogue on Steam :

http://store.steampowered.com/sub/4870/

plus they are now selling Myst V .

Cyan Worlds catalogue on GOG :

http://www.gog.com/en/catalogue#all_genres/search/cyan%20worlds/

:(

According to Cyan's website it'll be released here later this month.

Did they mention anything about Myst 4 ? (I know I could go to cyan site and check for myself but...) the fourth has always been my favorite of the series.

No, sorry. Newspost here: http://www.cyanworlds.com/news/?p=38

Seems odd to not try to release the entire series on GOG & Steam. What about Myst 3 & 4? Don't Ubisoft own the rights to the entire series?

Cyan games on Steam have some issues running on 7

They are also more expensive there than here to EU people due to steam's price differences

Great to hear that 4 and 5 are releasing on DD platforms soon but...weren't 4 and 5 published by Ubisoft?

Only 5 is going to be released soon, not 4. Ok thanks, well 5 is not the worse and I never actually finished it; so it will be a good occasion to when it's finally released on GoG.

Really? What's going to happen to 4 then? Any idea?

I remember watching my mom play Myst and wondering why she wasn't getting paid for such work.

It's not just 4, Myst 3 is also missing.

IIRC neither Myst 3 nor 4 were actually made by Cyan, that's probably why they are handled differently.

3 was made by Presto Studios (known for The Journeyman project), so those are already on GOG, though only in the form of Journeyman 2. Myst 4 was made by Ubisoft Montreal, so directly affiliated with Ubisoft.

Speaking about The Journeyman Project :
@TheEnigmaticT What happened with The Journeyman Project and The Journeyman Project 3: Legacy of Time ?

I think for the -50% coupons you could've used on the collection for the last 2 months since Xmas, and the 50% or more it'll probably have with every major sale that it's actually cheaper for us Euro's on Steam. Gog does great on individual games, but it doesn't compare well when there's collections out for the same game. Not to mention the collection on Steam includes the other 2 games, and it was still cheaper than the rest of the games together on the latest Cyan Worlds sale Gog just had.