The wiki and warframe-builder are two of the sites I always had up on Steam overlay when playing Warframe. I do miss slicing Grinner with Excal or going Hysteria with Valkyr but I got burnt out fast. Sigh might give the game another download.
But yeah Geno, the Wiki and Warframe-Builder are two of the best sites when playing Warframe. If you've installed Warframe from Steam, you won't have to worry about alt-tabbing every time you have to go on the sites.