The main purpose of this project is to avoid infamous
change -> restart and wait -> checkdevelopment lifecycle. Save&Reload during development should be standard and many other languages (including C#) contain this feature. Download and install DCEVM Java patch + agent jar and launch your application server with -javaagent option to get basic setup. Optionally add hotswap-agent.properties to your application to configure plugins and agent behaviour.
Each application framework (Spring, Hibernate, Logback, ...) needs special reloading mechanism to keep up-to-date after class redefinition (e.g. Hibernate configuration reload after new entity class is introduced). Hotswap agent works as an plugin system and comes preconfigured with all major framework plugins. It is easy to write your custom plugin even as part of your application.
None needed :) Really, all changes are transparent and all you need to do is to download patch+agent and setup your application server. Because we use standard java hotswap behaviour, your IDE will work as expected. However, we work on IDE plugins to help with download & configuration.