We are preparing a new osm2pgsql stable series release, 0.88.0. This is based off of the work done in 0.87 development series with porting to C++.
Help is needed in doing a last round of tests before release, in particular the z_order logic. 0.88.0-RC1 can be obtained from https://github.com/openstreetmap/osm2pgsql
If upgrading from a 0.86.0 or earlier created database, the schema migrations in https://github.com/openstreetmap/osm2pgsql/blob/master/docs/migrations.md are required.
Osm2pgsql is now C++ and requires the Boost libraries.
A new backend has been added, the “multi” backend. This allows multiple tables which can each contain different types of features. More documentation is available at https://github.com/openstreetmap/osm2pgsql/blob/master/docs/multi.md
In-database pending way tracking has been replaced with in-memory tracking, offering significant performance gains. This requires a schema migration for old databases.
z_order logic has been improved, taking into account recent work across multiple styles. https://github.com/openstreetmap/osm2pgsql/pull/374 has more information. This requires a schema migration for old databases.