What is Pluto?

Pluto is a superset of Lua 5.5 designed to assist with general-purpose programming & facilitate cleaner, more streamlined development via:

• A greatly enhanced standard library and pre-existing packages.
• More than a dozen highly-desired syntaxes such as switch statements, compound operators, string interpolation, classes, ternary expressions, enums, etc.
• A myriad of other improvements, such as generalized iteration, compiler warnings, and a preprocessor.

Despite the immense additions, Pluto remains highly compatible with Lua:

• (Mostly) compatible with Lua 5.5 source code.
  • Our only breakage is the addition of new keywords, which causes conflicts when those keywords are used as identifiers. However, Pluto leverages parser heuristics and — in cases where parser heuristics fail — Compatibility Mode to eliminate this concern. Most Lua 5.5 source code will execute flawlessly on Pluto.
• Reads and writes Lua 5.5 bytecode meaning it's forwards- and backwards-compatible.
  • Only some Pluto features generate backwards-incompatible bytecode, but they will say so in their documentation.
• Actively rebases with Lua's main repository. We are not a time-frozen dialect. Initially starting on Lua 5.4, Pluto has successfully performed a gradual rebase onto Lua 5.5.

With Compatibility Mode, Pluto has been dropped into large communities and did not break any existing scripts.

What does Pluto aspire to be?

Pluto aspires to be a version of Lua with a larger feature-set, that is all. Pluto is not a Lua-killer, an attempted successor, or any of that. Many people (rightly so) love Lua precisely because of the design philosophy. And fundamentally, Pluto is a major deviation from Lua's design philosophy. Some may prefer this, some may not.