Om is an experimental, unique take on concatenative languages with a focus on simplicity.
Defining features of Om include:
Extremely minimal syntax. Each program consists of only three syntactic elements: operand, operator, and separator.
Prefix notation rather than postfix. Instead of a data stack, functions manipulate the remainder of the program itself.
A unique "panmorphic" type system in which there is only one data type exposed in the language (a program), even though the implementation can optimize data representations for operations.
Unicode compliant and implemented using C++, Boost, and ICU.