Eigenfactor was developed by faculty at the University of Washington. Eigenfactor aims to measure a journal's total importance to the scientific community. Eigenfactor metrics are freely available; their algorithms use the structure of the entire citation network (as opposed to purely local citation information) to evaluate the importance of each journal.
Scimago journal rank is a tool that includes the journals and country scientific indicators (normalized on a scale of 0 to 100) that takes into account the number of citations to a journal, prestige of where those citations come from, and more. Scimago proves the major alternative to Web of Science's impact factor.
Scopus is a large citation database of peer-reviewed literature: scientific journals, books and conference proceedings with over 22,000 titles from more than 5,000 publishers. USU provides a tutorial on using this database.
An author's impact on their field or discipline has traditionally been measured using the number of times their academic publications are cited by other researchers. There are numerous algorithms that account for such things as the recency of the publication, or poorly or highly cited papers. While citation metrics may reflect the impact of research in a field, there are many potential biases with these measurements and they should be used with care. The Chronicle of Higher Education has a critique of author impact factors. See the Research Impact & Engagement guide for information beyond what is listed below.