Hulu is a free, ad supported streaming service. Content is limited to SD quality. Hulu Plus is Hulu's subscription service ($7.99/month), which offers more titles and in HD as well.
Hulu has no search API except a crude embedding helper service using oEmbed. I used it only to fetch an episode's name once I found the URL of that episode on Hulu, results are returned in JSON or XML. Searching was done by scraping the advanced search results page. I used jsoup to parse the HTML (I wrote about jsoup before). Overall it was much simpler then scarping Vudu because all of the relevant content was loaded statically with the HTML.