Since I also needed to fetch data from EntrezGene, and other NCBI web sites, I decided that’d I try out the EntrezAjax RESTful web service. Unlike NCBI’s eUtils API, EntrezAjax returns the results of queries as JSON datagrams, which makes it easier to integrate it into your web page.
The other nice thing about it is that it allows you to chain queries together. For example, in most cases, I don’t want to do a PubMed search, parse the article IDs that it returns, and turn around and fetch those PubMed records. That’s just a waste of time. I want to do the search and get useable data in one transaction, and EntrezAjax lets me do that.
The other nice thing about it is that it’s hosted on Google’s Appspot cloud infrastructure. Which means that the infrastructure can expand to meet the demands placed on it by developers.