The tour of L:

A language cannot be summed up as a list of features, because it is the combination of the features (and derived idioms) that provide the "feel" of the language. However, the following short list provides an appetizer:

• Open source implementation: The L compiler is licensed under the Cecill-C license, a copyleft and LGPL-compatible license that allows linking without restriction.
• A simple, familiar syntax optimized for readability: alignment and indentation, everything is an expression, separation with newline, simple grammar, optional type annotations...
• Algebraic datatypes and pattern matching for elegant retrieval of parts of an object.
• Parametric polymorphism allows to define code that work for any type, and does not require any type annotation or special syntax.
• First-class functions: pass dynamically-created functions as parameter to improve code reuse, factorize code, and make it more efficient.
• Static typing with complete type inference allows to combine the efficiency and early error detection of statically-typed language compiled language (e.g. C/Java/Ada), with the convenience and readability of dynamically typed ones (e.g. Ruby/Python/Lisp).
• Macros and syntax extensions allows to extend the language, from simple syntactic sugar to complex domain-specific-languages.
• Interpretation and native compilation to LLVM for efficient code generation.
• Mutable variables and imperative features for practical, efficient programming.
• Garbage collection improves the programmer productivity.
• Guaranteed optimizations allows writing performance-critical code in a readable form, and will ultimately allow writing low-level system code.
• And more

Want to know more? Have a look at the longer introduction, that will get you started!