BASIC programming language

This is for the programmic language, for simple games (basic games), see simple gameplay.

This tag is for interpreted BASIC. BASIC is, by default, executed from uncompleted code. There is a group specifically for compiled BASIC.

Implies the game is easily portable between an extremely wide variety of platforms.

Note, this is the original Microsoft BASIC based on Altair BASIC. Microsoft BASIC was the basis of AppleSOFT BASIC, Atari BASIC, Atari Microsoft BASIC, Commodore BASIC, Atari Portfolio BASIC, IBM BASIC (IBM ROM BASIC), IBM Advanced BASIC (BASICA), Microsoft GW-BASIC, VTech BASIC, TRS-80 Level II & Level III BASIC, OSI BASIC, KIM-1 BASIC, Epson BASIC, Tandy Color BASIC, MSX BASIC, and BASIC-80. Many Z80 platforms use BASIC-80 by Microsoft or it was available to buy from Microsoft for end users in addition to companies that licensed it for their own systems. BASIC-68 (for 6800 CPUs) and BASIC-69 (for 6809 CPUs) are based on BASIC-80 and were available to buy from Microsoft for end users or companies looking to license it.

The source code for Microsoft BASIC with complete documentation has been leaked but remains proprietary (therefore, not linked from UVL). But, it has been posted (by a user, not Microsoft) on a site owned by Microsoft where is said (by a user, not Microsoft) to be "This is free and unencumbered software released into the public domain." So, despite the illegality, it seems Microsoft isn't going to do anything about someone declaring their BASIC source code to be public domain.

Commodore BASIC applications can be run natively on Linux, Mac OS X, and Windows using cbmbasic; no emulator required; CPU independent. Speed depends about 1:1 on CPU MHz. A Commodore 64 representing 100% speed with its 1MHz CPU will be matched by anything else with a 1MHz CPU, whereas a 1GHz gets you 1000% of that speed.
run cbmbasic for interactive mode (its like booting a Commodore into BASIC)
run cbmbasic game.bas to run game.bas
or create scripts in Commodore BASIC language:
#!/usr/bin/cbmbasic
PRINT"HELLO WORLD!"