Two Firefox extensions can be substituted for Endnote that I found in an article and copied info below.
Scrapbook link to Scrapbook (or Alternate link if the other link is too long)
Zotero “What works even better is Zotero, a free Firefox extension that makes it easy to collect, manage, and cite your research sources. You can compare it to EndNote, a frequently used program to create research bibliographies, but Zotero is free and works within your browser. Not only can you create notes from webpages, save their location and export them in a formatted bibliography style it also works nicely with Google Books and Google Scholar!” Link to Zotero
BibMe: Another Web-based Bibliography tool
BibMe is a new web-based bibliography tool created as a software development project at Carnegie-Mellon. Unlike CiteULike and Zotero, two other powerful web-based bibliography tools that seem aimed at scholarly researchers, this tool seems geared primarily toward students. It strips down the bibliography process to simply typing in search terms. All one needs to do is type in a search term under the appropriate category, and a list of possible sources appears. Clicking on an option automatically generates a bibliography entry. Entries may also be manually entered if the source is not contained in the database. The tool lacks the social aspects of CiteULike, where one can peruse other users’ libraries or browse through tags, but it does have a suggested reading feature where similar sources appear under the bibliography entries. Sadly, the bibliography can only be exported to Rich Text Format, and I didn’t see an import option so that existing citations could be uploaded. It does seem like an interesting tool and probably useful for students.