Want to play some old school MTG without giving your credit card info to Magic Online?
Are you tired of Arena and its limited selection of cards?
Well it's your lucky day, I'm here to shill for the best community-based alternatives. This stuff runs on toasters and it's pretty easy to install and setup. Let's start with
>Cockatrice (Win/OsX/Ubuntu)
Still pretty popular, this basic software lets you play various tabletop games, including MTG.
You're supposed to play with your friends, as it lacks rules enforcement and AI.
>cockatrice.github.io
>Xmage (Win/OsX/Linux)
Written in java, this up-to-date Magic simulator fully implements rules enforcement (for 10000+ cards). It features a simple AI, but it's meant for two-player duels and multiplayer free-for-all games (up to 10 players).
You don't need friends, as you can play both on public and private servers.
It's by far the most popular choice when it comes to playing unrestricted Magic online with random people.
>xmage.de
>Forge (Win/OsX/Android/Linux)
Highly customizable, this Java game is clearly the most singleplayer-oriented of the bunch.
It features various AIs with different personalities and playstyles, full rules enforcement and nearly every MTG card/set/official deck ever released.
It's pretty solid if you want to test your deck or just fuck around with older cards from your childhood, but it also offers a fair amount of content and modes (Quest, duels, challenges, tournament, booster draft, puzzle etc).
You can also host games and play online against your friends, and it even features achievements.
>slightlymagic.net
>Wagic, The Homebrew (PSP,Win,Linux,iOs,Android)
This abandoned homebrew was mainly designed for PSP; it's old and outdated, yet it looks better than any other fanproject listed here.
wololo.net
Honorable mentions: Virtual Playtable, Untap, MagMa Magic Machine