Ur is a programming language in the tradition of ML and Haskell, but featuring
a significantly richer type system. Ur is functional, pure, statically-typed,
and strict. Ur supports a powerful kind of metaprogramming based on row types.

Ur/Web is Ur plus a special standard library and associated rules for parsing
and optimization. Ur/Web supports construction of dynamic web applications
backed by SQL databases. The signature of the standard library is such that
well-typed Ur/Web programs "don't go wrong" in a very broad sense. Not only do
they not crash during particular page generations, but they also may not:

  * Suffer from any kinds of code-injection attacks
  * Return invalid HTML
  * Contain dead intra-application links
  * Have mismatches between HTML forms and the fields expected by their
    handlers
  * Include client-side code that makes incorrect assumptions about the
    "AJAX"-style services that the remote web server provides
  * Attempt invalid SQL queries
  * Use improper marshaling or unmarshaling in communication with SQL databases
    or between browsers and web servers