Large scale experiment, such as, high energy physics and nuclear fusion experiments are executed with the cooperation of many institutes all over the world. Therefore, remote participation facilities are essential to establish the smooth cooperation. As remote participation tools, the web based application is ideal because they are downloaded each time when the user accesses to the web server, and the user can use the latest applications without installation. Also, the developers are not bothered by delivering them. Therefore, the authors have been developing web based applications for remote participation. Recently, the authors adopted Ruby on Rails as an application framework to develop the applications. These are data viewers, front end of the simulation programs, and the experiment scheduler and reporting tools. The main reason to adopt Ruby on Rails for this purpose is its great efficiency of developing web applications. In this presentation, the authors will introduce the actual application runs for LHD experiment, and discuss the usefulness of Ruby on Rails to develop the web based application for remote participations.