cross-platform

Neopets

1999 · Browser

Viacom

Teeworlds

2007 · Linux, Windows +1

Teeworlds Team

BatMUD

1990 · Linux, Windows +1

Cube

2001 · Windows, macOS

TORCS

2007 · Linux, Windows +1

Virtual Magic Kingdom

2005 · Browser

Disney Experiences

Torn (online text game)

2003 · Android, Browser +1

3Kingdoms

1992 · Android, Linux +3

Achaea, Dreams of Divine Lands

1997 · Browser, Linux +2

Iron Realms Entertainment

Ancient Anguish

1992

Discworld MUD

1991 · Linux, MS-DOS +2

Diversity University

1993

Dragon's Gate

1990

Elendor

1991

FurryMUCK

1990 · Windows

Hack

1982 · MS-DOS

LambdaMOO

1990

Pavel Curtis

LegendMUD

1994

Lost Souls (online game)

1990 · Android, Linux +3

MicroMUSE

1990

MorgenGrauen

1992

TubMUD

1990

Xyllomer

1991