WebMon!

Monitors your websites every 5 minutes, totally free. Get alerts by e-mail, SMS, Twitter or RSS. Add up to 50 websites. Monitors can be refreshed for an instant check with a click. Supports https and authentication with user/password.

ChangeDetection.com provides page change monitoring and notification services to Internet users worldwide. Anyone can use our service to monitor any website page for changes.

Distill is a web monitoring tool. It can monitor RSS feeds, a webpage or a part of webpage. Alerts in the form of pop-up, audio or emails can be received.

Update Scanner is a Firefox extension to monitor web pages for updates. Useful for websites that dont provide Atom or RSS feeds.

ChangeMon.Com lets you monitor any HTML page or RSS feed for changes. You can choose to be notified when a word/phrase is either added or removed from a web page, or you can choose to monitor only a specific part of a web page by visually selecting a target element. This service is completely free and doesn't require you to sign up for an account.

Track web page changes and get notified. Free Sign-up. Have all data in one place

Stays in the background and monitors web pages for changes.This extension allows your browser to monitor changes to web pages for you. It can inform you whenever a particular page changes without you having to go and check every time.

Create feed from elements (e.g. links) extracted from a given web page

WebSite-Watcher detects website updates and highlights all changes in the text. WebSite-Watcher monitors web pages, password protected pages, discussion forums and much more.

PageMon.net: we're watching!

Track web page changes in any web page daily for free users, every 30 mins for paid users - no RSS or Atom required. Receive notifications via Email, Notifo, Instant Message and SMS.

Uptime monitor for server. Currently fully free (beta) so it is subjected to change. Allows to monitor unlimited servers and websites. With custom CNAME you can create live status pages.

Follow That Page sends you an email when your favorite web pages have changed. The free version can perform 20 daily checks and 1 hourly check. You can enter any number of pages you like, but after checking 20 pages (in the daily run) it will stop and leave the rest for the next day.

Web page and json monitor, is an extension for the most modern browsers, It is used to monitor any Web page, such as a price at Amazon; A search on Google or more commonly where an RSS feed service is not guaranteed