Snowball is a small string processing language for creating stemming algorithms for use in Information Retrieval, plus a collection of stemming algorithms implemented using it. Snowball was originally designed and built by Martin Porter. Martin retired from development in 2014 and Snowball is now maintained as a community project. Martin originally chose the name Snowball as a tribute to SNOBOL, the excellent string handling language from the 1960s. It now also serves as a metaphor for how the project grows by gathering contributions over time. The Snowball compiler translates a Snowball program into source code in another language - currently ISO C, C#, Go, Java, Javascript, Object Pascal, Python and Rust are supported. This repository contains the source code for the snowball compiler and the stemming algorithms. The snowball compiler is written in ISO C - you'll need a C compiler which support C99 to build it (but the C code it generates should work with any ISO C compiler.) See https://snowballstem.org/ for more information about Snowball. What is Stemming? ================= Stemming maps different forms of the same word to a common "stem" - for example, the English stemmer maps *connection*, *connections*, *connective*, *connected*, and *connecting* to *connect*. So a searching for *connected* would also find documents which only have the other forms. This stem form is often a word itself, but this is not always the case as this is not a requirement for text search systems, which are the intended field of use. We also aim to conflate words with the same meaning, rather than all words with a common linguistic root (so *awe* and *awful* don't have the same stem), and over-stemming is more problematic than under-stemming so we tend not to stem in cases that are hard to resolve. If you want to always reduce words to a root form and/or get a root form which is itself a word then Snowball's stemming algorithms likely aren't the right answer.