Sphider 2.2.0 was released today in both the Classic and PDO editions.
There are currently no plans to release this update in PostgreSQL or SQLite editions. Those remain at 2.1.0. There seems to be little demand for these.
Sphider 2.2.0 has the search interface redesigned to be more mobile friendly. The code was rewritten to be more responsive to CSS instruction, made to detect the use of mobile browsers, and present a mobile friendly version of the standard template.
A minor security problem was also addressed, as well as the ability of the administrator to easily switch between the tabbed search (traditional, RSS, and image) and just the basic traditional text search.
There are plans for the next release (February 2019 ???) to expand this ability so that the administrator can pick and choose which search interfaces to present. If they want both traditional and image, but not RSS, they will be able to do so.
Also, the templates will be reworked so mobile browsers can experience friendly versions of ALL the templates.