I am employed to develop and maintain a desktop application for simulation and modelling with the engineering discipline. The application has been in developm

I am employed to develop and maintain a desktop application for simulation and modelling with the engineering discipline. The application has been in development for over 16 years. At inception a web application was totally out of the question. The application is CPU and RAM intensive. Until recently, this ruled out a web application. Amazon and other elastic compute providers have swung this pendulum a little. Model size generally exceeds the limits of Local Storage. The simulation can generate from hundreds of MB to multiple GB of data. While this can now be retrieved over the internet, the time to do so can become an issue. This will be compounded when the user wants to run sensitivity series (ie multiple models with slight variations). I have built a few CRUD web apps in my time. HTML+CSS+JS was incredibly painful compared to the desktop UI toolkits I have used. The models built in my application almost always contain client confidential information. Explaining to them that we/they have to send their data to "the cloud" in order to run the simulation is not going to be acceptable. Whenever I dip my toe into web development to see if things have improved, I still struggle to understand the convolutions required. Compiling CSS? How many JS libraries? I have to sacrifice how many chickens for my app to work right in IE+Firefox+Chrome+Safari+mobile? As far as I can tell, all the web app stuff is just to sidestep the need to install and update an application? While this might be an important consideration for a (IMHO lazy) IT department or for a communication based tool (Twitter/Facebook etc), it really doesn't make much sense to me for office applications and many other common tools. Why should I need an internet connection to do desktop publishing? Why do I need to transfer my possibly confidential data to someone else's computer just to transform it? These are things I have always been able to do with a desktop app, without having to compromise on privacy or performance.