This is an interpreter for the False language. Read the False language specification here. Another Javascript False interpreter can be found here, and this page has some more comments and False code samples.
Notes:
Multi-character variable names are allowed. Variable names can contain only alphabetic characters, are case-sensitive and can be arbitrarily long. However, in keeping with the False aesthetic, descriptive and informative variable names are discouraged, and multi-letter names should only be used once all single-letter names are exhausted.
The 'pick' opcode "ø" is implemented and the character ø is provided here for cut-and-paste convenience.
A new 'rotate n' opcode "®" is provided. '®' will pop an integer n from the stack, then move the n'th stack element to top-of-stack. This addresses the major shortcoming of the original False specification of not being able to modify the stack beyond the top 3 stack positions.
Input data via the pop-up input box, when required; enter a blank line or hit cancel to indicate end-of-input.
Output is unbuffered, and the 'flush' opcode "ß" is unimplemented and ignored.
Command-line arguments are not available.
The inline-assembly opcode "`" is unsupported. Instead, "`" can be used as a breakpoint for debugging False programs.
Other subtle differences exist between this interpreter and the original compiler (such as typecasting).