The primary development platform is CLISP on win32, but plain-odbc is also usable with CLISP on Linux with unixODBC.
High level features such as a special reader syntax for sql or mapping of CLOS objects to database tables are not part of plain-odbc.
The low level parts of the system consist of code from Paul Meurers sqlodbc module. The system uses now CFFI to interface to the ODBC C functions.
More Information can be found at the project page.