All languages that can build web application from open source languages (java, php, etc.) to vendor languages (.net), scripts (unix, groovy).
If you need someone focused on planning, budget and scope.
If you need someone focused on the skills management of your team.
Release - Team working
If you need to automate your release or setup a 100% clear release process in your company.
Content Management System
If you dont know HTML, you always have to contact your webmaster to add content to your website,... YOU
need a CMS !
Web Analytics Integrations
If you're wondering how your website or campaign is performing, you definetely need to setup some web-analytics tracker on your website.
Methodology is really important and depends on multiple factors such as project, team and company size, deadlines, etc.