Everysonnet is a site created to fill a need in the poet community. 
It lists at one internet address Every major sonnet form known* to exist in the English speaking world, along with example poems, and in many cases, helpful visual templates.  *Known to me, and known to be named.
It exists as a blog which differs from a ‘regular’ web site and takes some getting used to – I am still in the process of learning.  I’ll list here the things you most need to know to use this site.
1.It automatically puts the last post as the first thing you see, so I will always try to make this info, the last posted.
2.Perhaps the most useful tool for most is the list of all  Sonnet Forms.  Get there by clicking on the “Sonnet Forms” tab,
which is to the right of the “Home” tab.

Sonnet Rounds, Crowns and Sonnet Redoublé

Sonnet Crowns are simply a string of sonnets, each beginning with the ending line of the previous one and the final one ending with the beginning line of the first in the series.

A sonnet Corona is a string of 14 sonnets each of them starting with the last line of the sonnet before it.

A Sonnet Redouble’ is a similar series of 14 sonnets, followed by a fiftteenth made up entirely of the first line of the preceding 14.

I have found few in the the last decade and most are not truly composed of English Sonnets.

I have created a page that show all I have found.