Website Extension Paradigms are primarily ways of extending functionality of a website by a service of a third-party provider.  This trend has emerged in recent years and is growing rapidly with the explosion of websites offering API support (Click to learn more about API).  This opens the door for innovation in business model by combining data from various APIs in interesting ways, in what are called Mashups.   

ProgrammableWeb.com reports that Social, Internet, Telephony, Reference and Government have added more than 2000 APIs in 2011.  Most of these APIs allows you to make a limited number of calls for free and charge for higher usage.  With proliferation of technologies like Apache Hadoop it is now possible for companies to analyze, process and extract intelligence like never before (thanks to companies like Pentaho, Cloudera and Hortonworks).  Companies can now leverage this intelligence and sell it through their APIs.

By Website Extension Paradigms I mean:

• Extending a website’s functionality by utilizing third-party software and services.  For example, a commenting system.
• Another form of extension is to host your service on a third-party domain and extend their functionality (Think Facebook Apps).
• Mashups

I am planning to write a series of blog posts where I will explore different services and platforms that are used in this context.  In this post I will focus on various commenting systems that are in the market today and as a publisher you can use this as a guide in choosing a commenting system for your site/blog.

Some important criterias to consider while choosing a commenting system:

* Real Time comments
* Comment Moderation with multiple moderators if you need
* Anti-spam
* Search Engine crawl-ability
* Social Integration
* Notifications on new comments and replies
* JavaScript librarie(s) that the product uses and make sure there are no conflicts

Disqus: http://www.disqus.com/

Realtime comments – Both posting and updating
Inline media embedding – Youtube, Flickr etc
Fully compatible with mobile websites for commenting while on the go.
Comment Storage: Stored in Disqus and can optionally be synced with your blog provider
Akismet: Protection from web spam
Notification: Subscribe via RSS or email
Like button support for both the page and individual comments
Reactions – Pull mentions of your page on Twitter back into the Disqus conversation on your own site
Comment sorting options include popular now, best rating, newest first, oldest first, etc.
Used By: CNN, Time, Fox News etc.

Echo: http://aboutecho.com/products/real-time-comments.html

Realtime comments – All comment streams are updated without need for manual refresh
Top Commenters – Moderators can mark users as Top Commenters and those comments will automatically bubble up
A cloud service called Echo StreamServer which stores all comments.  They can be retrieved as Activity Streams
PostRank – Intelligent comment ranking algorithm
Integration with Social Networks
Multiple Sort Orders – Like most recent, most popular comments
White Label Solution – Fully customizable look and feel
Analytics – Get insights.  Slice data by article, data source and date ranges
Integrates easily wherever JavaScript is supported
Subscribe via RSS or email

DiscussIt: http://www.pnyxe.com/DiscussIt-comment-system

Author Reputation
Search engine indexing
Automatic SPAM and profanity filters
Automatically inherits your web design
Inserting polls into posts
Integration with popular social networks
Free version available and has most features with Ads

InstaComments: http://www.instacomment.com/

Fully hosted, no download needed
Inserting polls into posts
Data migration from existing system
Comment Ranking
Author reputation
Different versions are available at different price ranges with varying features
Integrates well on Blogger, WordPress, Tumblr, WordPress, Weebly and more
Full moderation over posts

Intense Debate: http://www.intensedebate.com/

Owned by Automattic (Strong WordPress support)
Comment Threading – Reply directly to specific comments with nested replies
Email Notifications – Respond to moderate comments via email
Subscribe via RSS
Guest Commenting – No Account or Sign up necessary
Integrates with Facebook Connect, Twitter, Gravatar, etc.
Trackbacks and Linkbacks are synced
Widgets for comment stats, most popular posts, etc.

Livefyre: http://www.livefyre.com/

Social User Tagging:  Tag Facebook and Twitter friends from inside the comment box
Allow users to Sign In using their Social Networking credentials which includes Facebook, Twitter, Google, LinkedIn and also OpenID
Users can share their comments in their favorite social networking sites
Real-time interaction with comment bubbles, new listener count.
Search engine crawlable
Follow conversations through email
Allows comment ratings
Linkback – Lets the other Livefyre bloggers leave link to their latest post
Integration with Blogger, Drupal, etc. is on their development plan

Facebook Comments: http://developers.facebook.com/docs/reference/plugins/comments/

Part of Social Plugins
Must be associated with a Facebook Application
Look and feel cannot be customized
Optionally post on your Facebook News Feed
No integration to other social networks
Used by Techcrunch