CCL: question on free patents online database

[Andrew Voronkov <drugdesign-$-yandex.ru>]

 Sent to CCL by: Andrew Voronkov [drugdesign*_*yandex.ru]
 Dear CCL users,
 I am curious about how Free Patents online was created. It s a very nice
 service, but for the last time it s almost all the time not available. I wonder
 where and how approximately the mine and get chemical structure-patent
 information. It would be nice to do something similar.
 Best regards,
 Andrew