Dose 'klayout' widely used for editing layouts in this open-source field? I developed scripts to connect laygo2 and magic for design automation(Example). If the klayout is also commonly used, I could make similar scripts for klayout.

klayout was originally designed for viewing layouts, not for editing them, so adoption has probably been slower as people realize it has capabilities that it didn't before. But yes, it is being used pretty widely now for design work.

I am using 'KLayout' to design Silicon photonics based devices and circuit. SiEPIC tools and pdk and few more newly developed pdks can be installed. Scripting is also available using Python and Ruby.