PubMed was first released two decades ago in January 1996 as an experimental database under the National Center for Biotechnology Information (NCBI) retrieval system. The word “experimental” was dropped from the website in April 1997, and on June 26, 1997, a Capitol Hill press conference officially announced free MEDLINE access via PubMed.

See an outline of the early years in the article, PubMed Celebrates its 10th Anniversary!

PubMed continued to evolve and in 2007, the NCBI retrieval engine was completely redesigned to provide a foundation for the discovery initiative. In 2008, highlights included a number of discovery tools such as, an “also try” feature, query terms in article titles display, and a drug sensor. Collections were added to the My NCBI user tools, automatic term mapping was enhanced, an advanced search feature was added, and citation and gene sensors were released. The PubMed citation sensor continues to be one of the most popular discovery features; users love it!

Highlights for 2009 included a recent activity feature that tracks up to six months of a user’s NCBI database searches and viewed records, an autosuggest feature, and a totally revamped, user-friendly interface. Feedback from users on the redesigned interface was overwhelmingly positive.

From 2010 to 2011, the PubMed advanced search page was reformatted, a new limits page was released, search terms were modified to automatically display in bold, a CSV selection was added as a “send to file” option, and structured abstracts and images were added to the abstract display. PubMed Mobile was launched for users with limited screen size or on handheld devices. Enhancements were made to the My NCBI My Bibliography feature to assist NIH-funded investigators with tracking and reporting their peer-reviewed publications. The MeSH database and the Clinical Queries pages were redesigned to provide the same streamlined interface previously released in PubMed.

In 2012, the My NCBI My Bibliography collection was enhanced with links to similar articles and cited in. Discovery tool additions included the popular “results by year” graph and a PubMed Central images display. A facet sidebar replaced the limits page and the abstract display “author link” was updated to display results using a computer ranking algorithm to facilitate author name disambiguation. The “send to” menu was augmented with an export to citation manager option. A “save items” widget was added to the abstract display to provide an expedient way to add citations to a My NCBI collection.

In 2013 to 2014, author keywords and social media icons were added to the abstract display and PubMed started accepting and displaying non-English abstracts. A new “relevance sort” option was released, and a way to download your entire history was added to the advanced search page. PubMed began indexing multiple author affiliations. PubMed Commons was released as a way for authors to share opinions and information about scientific publications in PubMed. Additionally, PubMed increased the addition of new citations from five to seven days a week.

During 2015 to the present, the trending articles and “frequently viewed together” discovery tools were released. Fuzzy matching to rescue zero results was improved. Additional knowledge panels and sensors were released; for example, the query “human genome blast” now presents a tool for the user to run a BLAST search from within PubMed. PubMed hit the milestone of 26 million citations; over one million citations are added every year.

The near future will include a new PubMed data management system that will streamline data submission for publishers and provide an interface for immediate correction of citation errors.

Cheers to PubMed!

Here’s to another 20 years of excellence, evolution, and discovery.

By Kathi Canese, NLM National Center for Biotechnology Information

Note: This article originally appeared in the NLM Technical Bulletin June 21, 2016.