Requality is an Eclipse-based Requirements Management Tool that supports both development of requirements from scratch as well as recreation of a hierarchy of requirements from existing documents. Requality keeps linkage between a requirement and fragments of documents that became a source for the requirement that makes Requality very attractive for reverse engineering of requirements. Another important feature of the tool is a support for Requirements-based Test Purpose Design.
Installation instructions are available here.
User guide is available within Eclipse Help System: Help->Help Contents->Requality.
Online manual: http://requality.ru/en/doc.en.html
Requality consists of java library implementing hierarchic database of requirements and Eclipse IDE extension. It allows you to build and to manage a hierarchy of requirements. Each requirement can store a link to one or more fragments of documents the requirement originates from. Internally all the documents are stored in HTML format, but the tool provides means to import .doc and .pdf documents as well.