Indexing Software programs are tools to build a book index . 
There are several methodologies for indexing: 
- Embedded indexing includes the index headings in the midst of the text itself, but surrounded by codes so that they are not normally displayed. A usable index is then generated automatically from the embedded text using the position of the embedded headings to determine the locators. Thus, when the pagination is changed the index can be regenerated with the new locators.
- Tagging allow indexing codes to be embedded in the text after the indexing is complete. The indexer inserts numbered dummy tags in the files, and then builds the index separately
- Most Word processors have integrated automated indexing functions. These tools build a concordance or word lists from processed files. They have often limited use.
List of tools
The most well-known indexing tools are: 
- SKY Index
- Index (publishing)
- ^ Jump up to:a b “Software” . The American Society for Indexing . Retrieved 2017-01-07 .
- Jump up^ “DEDICATED INDEXING SOFTWARE: WHAT IT CAN DO FOR YOU” (PDF) . Indexers.org . Retrieved 2017-01-07 .