I want to publish an R Shiny web application (http://www.rstudio.com/shiny/) on the web, but I want to password protect it so that only people with credentials can view what I h
This could be viewed as an HTTP
requirement rather than a Shiny
feature. If so, you could look into first implementing an HTTP authentication, and once the credentials are verified, you can redirect to your Shiny app URL.
Here's a blog post that explains setting up simple authentication for Apache Tomcat.
Also, take a look at this article for setting it up in IIS
Searching SO or the Web for basic authentication should get you a few useful links and get you closer.