This is list compiled by ReadWriteWeb:

AllVoices; Breaking News, Current Events, Latest News and World Events.
bit.ly (betaworks); URL redirection service with real-time link tracking.
BoilingPage; Find popular webpages among people in real time.
Cleartext; Enterprise Messaging Software as a Service.
Cliqset; Merging, Organizing and Sharing Social Information.
Cluuz; Web search engine featuring semantic cluster graphs, image extraction, and tag clouds.
Collecta; monitors the update streams of news sites, popular blogs and social media.
CrowdEye; Real-time Social Search.
Daylife; A point & click tool to create dynamic content portals.
Faroo; Real Time Search.
FirstRain; search-driven research.
Fwix; a local news site designed to show you the most recent and relevant information in your area.
Google; adding real-time web to search.
HighNote; Search, track and share the real-time web.
Insttant; Real Time People Generated News.
Isode; Messaging and Directory Server Software.
itpints; Real-time web search engine.
Jive Software; Social Business Software (SBS).
JS-Kit ECHO; next generation commenting system.
Kaazing; Enterprise Gateway extends real-time messaging and live data delivery to the Web.
Lexalytics; Sentiment and Text Analysis.
Liaise; an email add-on that analyzes the free-text contents of your emails as you write them.
MicroPlaza; Popular topics and news from the Twitter public timeline.
oneriot; real-time search engine.
PBworks; Collaboration, Intranet, Extranet, Project Management.
PeopleBrowsr; Social Search, Sentiment and Conversation Mining Dashboard.
Perpetually; keep up to date on your competitors.
PostRank; Discover the best blogs, find and follow topic experts and influencers.
Present.ly; a micro-blogging communication tool for your company.
Radian6; Social Media Monitoring, Measurement and Engagement.
Real-Time Innovations; Real-time messaging middleware and design expertise.
reddit; User-generated news links.
Scoopler; real-time search engine.
Scout Labs; web-based application that finds signals in the noise of social media.
Seesmic; manage your lifestream from Facebook & multiple Twitter accounts.
Shareaholic; An extension to share and bookmark web-pages on popular social sharing and bookmarking services.
Superfeedr; Real-time feed parsing in the cloud for web-developers.
Surf Canyon; Free Browser Add-On for Real-Time Personalized Search.
Sysomos; Business Intelligence for Social Media.
Thoora; delivering the news attracting the most buzz and discussion.
TIBCO; business integration and process management software company that enables real-time business.
Topsy; search engine powered by tweets.
tr.im; URL shortening.
Tumblr; light blogging service.
Tweetdeck; desktop Twitter client.
Twitter; micro-blogging.
Vayusphere; an enterprise software company dedicated to the acceleration of a corporation’s time critical and frequently used business processes.
WebTrends; Enterprise Customer Intelligence.
Wowd; a tool for finding popular information, in real-time.
Yauba; Privacy safe, real-time search engine.

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