Long history.
Most popular somwhere around 1980.
Unfamiliar syntax.
Allows exotic identifiers.
Conventionally uses hyphen as a word delimiter in long identifiers.
(Usually) no type declarations.
Extensible syntax (actually programmable).
Comfortable metaprogramming.
Interactive and incremental development.
Resident symbol table.
Intermingles load time, compile time, and run time.
Many diverse dialects.
Light-weigh data structure with single method.
Linked lists play a central role.
Favours small procedures.
Multiple return values.
Used as a secret weapon.
Used as a scapegoat.
Attracts fanatics.
Attracts trolls.
Special-purpose hardware implementations.
Standardised 1994.
Vocal minority rejects standard.