Is there anything similar and lightweight that is cross-platform(or at least is available both on Linux and OS X)? I am not a Windows user, so that's a secondary priority for me
I'm working on a multi-platform code editor similar to notepad++ and some new editors like Zed, called ecode, that tries to be a fresh take on code editors using some modern tools and technologies like LSPs. I started working on it after using Geany (which was the closest alternative to notepad++ in Linux) for many years but finding Geany lacking some essential features for my needs. ecode is developed with speed in mind and has a very fast startup time. It might be a good fit for your search.