Online Solitaire is described as 'Play a free online version of this classic Solitaire game. No registration or download required. Ad-free. 10000+ free solitaire games. Freecell, Spider Solitaire & Klondike' and is a Card Game in the Games category. There are more than 25 games similar to Online Solitaire for a variety of platforms, including Android, iPhone, Android Tablet, Online / Web-based and iPad. The best alternative is Simple Solitaire Collection, which is both free and Open Source. Other Online Solitaire like games are SolSuite Solitaire (Paid), PySolFC (Free, Open Source), XM Solitaire (Free, Open Source) and AisleRiot (Free, Open Source).
SolSuite Solitaire is a high-quality collection of solitaire games. All your favorite games are implemented: Spider solitaire, Klondike, FreeCell, Pyramid, Golf, Busy Aces, Canfield, Forty Thieves, Four Seasons, Carpet, Flower Garden, Rouge et Noir, Monte Carlo...
200 card games (Freecell, Klondike, Fan, Spider, Pyramid, Gaps, ...). Games layout and rules are declared in XML format. User can add his own cards and background BMP images. Right-click moves a card to the most suitable cell according to game rules.
Aisleriot (also known as Solitaire or sol) is a collection of card games which are easy to play with the aid of a mouse. The rules for the games have been coded for your pleasure in the GNOME scripting language (Scheme).
Solitaire Planet is an immersive and highly configurable 3D solitaire collection for the desktop and mobile. Enjoy a whole world of solitaire games. Escape for minutes or for hours, you can always come back for endless entertainment.
Solitaire.gg provides a huge collection of solitaire games including Klondike, FreeCell, Spider and many more. The entire collection is open-source and also playable online with just the right amount of options to configure basic settings and appearance.