[NTG-context] How to create multiple PDFs from one TeX file?

I have several books in a set that have many things I'd like to have linked together, such as page references, shared indexes, shared glossaries, etc. One solution I see is putting all the files together, then using a tool like pdfjam to seperate the pages later, but I'm wondering if ConTeXt can already produce multiple files, or a split in the PDF, already? I tried this code below, as I hoped it would create two PDFs, but it only rendered everything between the first set of `\starttext` and `\stoptext`. --Joel Minimum example: \starttext This is document 1. \input knuth \stoptext \starttext This is document 2. \input knuth \stoptext