A large collection of freeware card games for Windows are on FreewareFiles.com. Its card games include Solitaire, Cribbage and Blackjack. It has both single player and multiplayer games. The free website CardGames.io has many card games available to play online. Although browser-based card games don't require installation, downloadable games may include more features or stability.
FreeWareFiles.com has dozens of free card games from around the world. Most of the games on FreeWareFiles.com only work on Windows computers; however, some of its card games may also have versions for Mac OS X, Android and iOs. Certain multiplayer games support playing across multiple platforms.
A much simpler option is the website CardGames.io, with browser-based card games that work on any OS. As of 2015, CardGames.io has 17 games on its site, including Crazy Eights, Sudoku and Yahtzee. Its games are simple and include no way of saving a game or making any rule variations. CardGames.io frequently adds new games or improvements to current ones.
The web-based Pogo has over a dozen online card games that work with the browser-based Java plug-in. Pogo also has an optional system called Jackpot, where winning coins in-game earn players a chance at winning a Rewards Card or in-game gems. Pogo has both single player and multiplayer card games on its website, which can be played with or without registering.