I have just started reading this book and came across 'Progressive Enhancement'.
I'm just wondering, to what extent is it necessary to provide as much functionality as possible to the end user ? I mean if some one has blocked Javascript or is using some ancient browser, is it really necessary to cater to such users at the expense of slower development oryour other users who are using cutting edge browsers ? Does progressive enhancement mean that I should use the new input types (date, color etc) in HTML5 ? Because that would mean I'm not relying on Javascript or CSS to serve my content.