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).