PubSub was a prospective search

Prospective search

Prospective search, or persistent search, is a method of searching on the Internet where the query is given first and the information for the results are then acquired...

 engine for searching blog

Blog

A blog is a type of website or part of a website supposed to be updated with new content from time to time. Blogs are usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in...

s, press releases, Usenet

Usenet

Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...

, USGS earthquake alerts, SEC filings and FAA Flight Delay information.

The site, founded in 2002 by Bob Wyman and Salim Ismail, operated by storing a user's search term, making it a subscription, and checking it against posts on blogs which ping

Ping

Ping is a computer network administration utility used to test the reachability of a host on an Internet Protocol network and to measure the round-trip time for messages sent from the originating host to a destination computer...

 the search engine. When a new match was found, the user was notified, even if it occurred months after the initial search. This feature led PubSub to call itself a matching engine. It also checks incoming Usenet posts, USGS earthquake alerts, press release via NITF, SEC filings and FAA flight delay information.

Results could be read on the service's website, or on an optional sidebar, available for both Internet Explorer

Internet Explorer

Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...

 and Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...

, written by Malcolm Pollack and Duncan A. Werner respectively, or via RSS

RSS

-Mathematics:* Root-sum-square, the square root of the sum of the squares of the elements of a data set* Residual sum of squares in statistics-Technology:* RSS , "Really Simple Syndication" or "Rich Site Summary", a family of web feed formats...

. Results could also be delivered to remote systems via Restful APIs, email or XMPP

Extensible Messaging and Presence Protocol

Extensible Messaging and Presence Protocol is an open-standard communications protocol for message-oriented middleware based on XML . The protocol was originally named Jabber, and was developed by the Jabber open-source community in 1999 for near-real-time, extensible instant messaging , presence...

Financial trouble

PubSub got into something of a problem as noted in this blog entry by Bob Wyman and now appears to be dead.

"Our days are numbered. A recent attempt to execute a merger has been blocked and we've been blocked from raising equity financing that would allow us to continue to pay salaries and pay off our $3 million in debt. Thus, our "doors" will close soon if we can't find someone to pull us out of the current situation. Persons with fast access to cash and a desire for some of the industry's best technology are advised to contact us rapidly...

The PubSub website was offline from 15 January 2007 until 15 August 2007. Its assets were purchased by Something Simpler. Something Simpler is preparing to relaunch the site as a user friendly version of Yahoo! Pipes

Yahoo! Pipes

Yahoo! Pipes is a web application from Yahoo! that provides a graphical user interface for building data mashups that aggregate web feeds, web pages, and other services, creating Web-based apps from various sources, and publishing those apps...

. Something Simpler is planning to launch a Facebook

Facebook

Facebook is a social networking service and website launched in February 2004, operated and privately owned by Facebook, Inc. , Facebook has more than 800 million active users. Users must register before using the site, after which they may create a personal profile, add other users as...

application similar to the original PubSub sidebars.

As November 18, 2009. The PubSub v2.0 is officially public accessible again.