Current trend of web 2.0 outdates heavy proprietary technology and upholds lightweight adaptive and communicative technology as its backbone. However there is a chance of getting lost as too many new technologies are emerging. We recommend following technologies to minimize hassle of maintenance as well as saving setup cost.
Linux, Apache, MySQL, PHP
MySQL, Memcached, SAN
CodeIgniter, CakePHP, RoR
Smarty, Template Lite, XSLT
JQuery, mootools, ExtJS, YUI, Ajax
HTML5, CSS, XHTML
Microformats
Tagging
RSS, XMLSitemap, Pinging, Opensocial, widget
REST, XML, XML/SOAP, JSON-based APIs
EVB, Widget, Silent vote
oAuth, OpenID