Background: F1000 Workspace, Mendeley, EndNote Basic (without Web of Science), and EndNote Desktop/Online are tools that facilitate building shared libraries of references with attached PDFs for groups such as research labs, medical residents and co-authors. This evaluation compares specific functionality of these tools to help librarians match recommendations with user needs. Methods: The structured evaluation includes these metrics: sharing; access; importing citations, PDFs, and databases; duplicate removal; ability to organize and make notes; ease of installing a word plugin; styles available for bibliography references; ability to upload and track versions of a co-authored article; and product support. Results: Sharing: F1000W and EndNote offer unlimited shared ”projects” and “groups,” respectively, although whole libraries may not be shared with EndNote Basic. EndNote desktop allows syncing one library with an online account. All the references in this library can be shared from the desktop with other EndNote v.7+ users, or by sharing groups within the library via the online account. Desktop users can accept unlimited library sharing invitations. Free Mendeley accounts offer one private group with 3 members. An institutional license provides unlimited groups with 25 members. Access: F1000W and EndNote Basic are entirely web based. Mendeley and EndNote are desktop based with online interfaces. Importing: All programs have browser web importers and import files in a variety of standard formats and, with the exception of EndNote Basic, will create records from PDFs of articles with DOIs. Deduplicating: F1000W merges exact duplicates on import. All products have tools to identify and merge duplicates upon verification. Organizing in shared groups: Mendeley has shared multi-level folders and tags; other products share just folders. Notes: All products, with the exception of EndNote Basic, provide highlighting and notes within stored PDFs. Mendeley and F1000W display PDF notes in the records and notes can be directly added to the records. Citing tool: Word plugins are easy to install for all programs. F1000W has a Google Docs add-in. Styles: EndNote Basic has 21 styles, while the other programs provide hundreds. Editing styles is available via support request in F1000W, in EndNote Desktop but not in EndNote Basic, and in Mendeley for those with scripting skills. Manuscripts: F1000W has a manuscript sharing tool with version tracking. Support: Response time to support requests are shortest in F1000W. Conclusions: The poster details user needs and tool recommendations in 4 cases: medical resident, public health student, systematic review team and research lab.