ANTLR, ANother Tool for Language Recognition, is a language tool that provides a framework for constructing recognizers, interpreters, compilers, and translators from grammatical descriptions containing actions in a variety of target languages.
Flex (fast lexical analyzer generator) is a tool for generating scanners. A scanner, sometimes called a tokenizer, is a program which recognizes lexical patterns in text. The flex program reads user-specified input files, or its standard input if no file names are given, for a...
textX is a meta-language for building Domain-Specific Languages (DSLs) in Python. It is inspired by Xtext.
It will help you build your textual language easily. You can invent your own language or build a support for an existing textual language.