The ACM Portal includes two databases: the ACM Digital Library that is a full text collection of every article published by ACM, including over 50 years of archives, and the Guide to Computing Literature that is a bibliographic collection from major publishers in computing with over one million entries.
JabRef can download citations from the ACM Portal database. To use this feature, choose Web search -> Search ACMPortal, and the search interface will appear in the side pane.
To start a search, enter the words of your query, and press Enter or the Fetch button.
This causes a significantly larger amount of network queries, so to avoid excessive pressure on the ACM Portal web site, JabRef will refuse to download entries for more than a given number.
You may choose which database to search and you may opt to download the abstracts along with the cite information for each entry, by checking the Include abstracts checkbox.