I follow picolisp and J as well and I would consider them niches which have their fans and get referred by fans to newcomers. Both are great projects by the way.
Not sure what the relationship between niches and website appearance is here.
I only care about quality, not quantity or popularity when selecting my tools for a task. There are people doing real work with both J and PicoLisp. Look at KDB+/Q. It is a highly effective time series database/language that is used by some of the largest companies, but could be called niche, yet the kx.com site is modern, but look at kxparc.com which is Arthur Whitney's site. He created A+, K and Q, and inspired J, yet the site is basically plain text and minimal, the beginnings of a desktop and server OS in K, KOS.
BTW, J has Jd, a time series dbase with J as the built-in language of you're interested in that sort of stuff.
I am more a "function over form" kind of guy, although I understand the importance of appearance and human interface designs.
