NetBeans comes with "Compile On Save" and editing support for http://sass-lang.com and http://lessframework.com out-of-the-box. No plugins required.
See you at Java EE User Interfaces, HTML 5 or Virtual Dedicated Workshops / consulting!
NEW online workshop: WebStandards Igniter (online)
Airport MUC workshops: Java EE 8, Java 9: Bootstrap, Effective, Architectures, Single Page Apps, Progressive Web Apps, HTML 5, ES 6, CSS 3 and Microservices
Podcast: airhacks.fm and newsletter: airhacks.news
A book about rethinking Java EE Patterns