Primarily proprietary developers have also helped free gaming by creating free libraries. Loki Software helped create and maintain the Simple DirectMedia Layer and OpenAL libraries and Linux Game Publishing created and maintained the free network layer Grapple. LGP also avoided publishing games similar to popular free titles. Many libraries/infrastructures have been created without corporate assistance however, such as the online game system GGZ Gaming Zone, Gamerzilla achievement integration, GamingAnywhere cloud streaming, Mumble voice over IP, OBS Studio for screencasting, and the Lutris game manager. Physics engines such as Box2D, Bullet, Chipmunk, OPAL, Open Dynamics Engine, Tokamak and Newton Game Dynamics have been made available as open source. In addition, various game creators are free software such as the ZZT remake MegaZeux, versions of Game Editor, Adventure Game Studio, OHRRPGCE, Game-Maker, the engine behind Stencyl, the original Construct, GDevelop and Godot. Rise in popularity and diversity Individuals and teams have continued creating many popular free software games, starting really in the late 1990s to the present day. Many of these are clones such as Pingus, Lix, and Rabbit Escape (Lemmings), Enigma (Oxyd), TetriNET (Tetris), Ace of Penguins (Microsoft Solitaire), Crack Attack (Tetris Attack), Pathological (Logcial), FloboPoyo (Puyo Puyo), BurgerSpace (BurgerTime), Einstein Puzzle (Sherlock), UltraStar (SingStar), OpenClonk (Clonk), FreeGish (Gish), I Have No Tomatoes (Dynablaster), Scorched 3D and XScorch (Scorched Earth), FreeVikings (The Lost Vikings), Penguin Command (Missile Command), Paranoid (Breakout), Sable (Space Harrier), Circus Linux! (Circus Atari), Gem Drop X (Gem Drop), Fish Supper and Froggix (Frogger), OpenMortal (Mortal Kombat), Triplane Turmoil (Sopwith), IceBreaker (JezzBall), Monsterz (Bejeweled), Tux Football and YSoccer (Sensible Soccer), iMaze (MIDI Maze), Surge the Rabbit (Sonic the Hedgehog), Dave Gnukem (Duke Nukem), Minetest (Minecraft), Tile World (Chip's Challenge), FreeOrion (Master of Orion), Tuxánci (Bulánci), Super Tux Party (Mario Party), Neverball (Super Monkey Ball), Kraptor/RafKill (Raptor: Call of the Shadows), Trackballs (Marble Madness), Hurrican (Turrican), OpenTyrian (Tyrian), HexGL (Wipeout), Zaz (Zuma), Ostrich Riders (Joust), Endless Sky and Naev (Escape Velocity), Pioneer and Oolite (Elite), SuperTux, Secret Maryo Chronicles and Mari0 (Super Mario Bros.), WarMUX and Hedgewars (Worms), OpenLieroX and LieroLibre (Liero) as well as Frets on Fire (Guitar Hero), and StepMania (Dance Dance Revolution). A number of these games and those mentioned earlier and later in this section have even received mainstream press coverage and have helped to establish free gaming as a moderately popular pastime, even if mostly enjoyed by Linux, BSD, some Macintosh and even a