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Jekyll is a highly popular SSG. It is well documented, and supports quite a lot of features out of the box. It does have some specific structure specifics enforced on the project and content however. It also seems quite a large project with much documentation which can be a catch 22 for this problem at the start, but may be something to look at once we have some initial SSG in place. Jekyll doesn't seem to support HTML files as content or if it does, it is a plugin which was not easily located, and expects a Markdown fileOne issue with Jekyll is the use of Liquid. Groovy, Thymeleaf, and Freemarker templates can do some really nice logic if we need it, and Jekyll is meant to be a secure environment for Github pages. At first, it appeared to not support .html files in structured content, but after another review per some dev list comments, that does seem possible.
Metalsmith (Node JS)
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Per the SSGs reviewed it seems Nikola or Metalsmith would probably be good evolutions if JBake and Gradle can not keep up with where the projects needs travel, and with a little more time with those tools, they seem likely to be successful. Jekyll may also be a good option, but it would depend on its allowed structures, but it certainly has many plugins and tools which front end developers find useful, but one must use Liquid for its templates, and only Liquid, but Nikola supports HTML content out of the box, and Metalsmith may be able to support such a notion going forward or already by way of a plugin along with many tools front end developers find useful.
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