Blast
(Basic Local Alignment Search Tool) is a set of similarity search programs designed to explore all of the available sequence databases regardless of whether the query is protein or DNA. It is more than a tool to view sequences aligned with each other or to calculate percent homology, but a program to locate regions of sequence similarity with a view to comparing structure and function.

Gbrowse

GBrowse is a combination of database and interactive web pages for manipulating and displaying annotations on genomes.