Bobby(http://www.cast.org/bobby/) online web page accessibility test. Make your site accessible to people with disabilities.
WebTV Browser(http://developer.msntv.com/Tools/WebTVVwr.asp) WebTV compatibility. See how WebTV users see your web site.
Older Browsers(http://www.upsdell.com/BrowserNews/find.htm#oldies) Older browsers for testing purposes. Download any browser version here.
Browser-Safe Colors(http://www.bookmarklets.com/tools/design/index.phtml) Javascriptlet of safe computer colors for web pages. Put this tiny javascriptlet of 216 browser-safe colors on your browser toolbar.
S-Rule(http://www.kagi.com/microfox/) Onscreen ruler to measure width & height of HTML elements
NoteTab(http://www.notetab.ch/ntl.htm) An intuitive NotePad replacement and HTML editor, with spelling/thesaurus/document-to-HTML capabilities
StyleMaster(http://www.westciv.com/style_master/index.html) with online CSS tutorial (http://www.westciv.com/style_master/academy/css_tutorial/introduction/index.html)
w3.org(http://www.w3.org/TR/REC-html40/present/styles.html#idx-styl) a tutorial and guidelines for style sheets
Internet Tools
Zone Alarm(http://www.zonelabs.com/) FREE personal firewall software, for Internet security
PandaSoftware.com(http://us.pandasoftware.com/) Antivirus software and e-mailed security alerts
iClean(http://www.aladdinsys.com/iclean/moreinfowin.html) You'll be amazed at the number of deletions ("cookies", popups, etc.) after clicking the CLEAN button.