Versions of PostgreSQL supported by which versions of PostGIS

PostgreSQL Version	PostGIS 1.3	PostGIS 1.4	PostGIS 1.5	PostGIS 2.0
7.2-7.4	Yes (not windows)	No	No	No
8.0	Yes (not windows)	No	No	No
8.1	Yes	No	No	No
8.2	Yes	Yes	No	No
8.3	Yes	Yes	Yes	Yes?
8.4	Yes	Yes	Yes	Yes
9.0	No	No	Yes	Yes
9.1	No	No	Yes?	Yes

For the question mark items Yes? support may be dropped for those before those products are officially released. PostgreSQL 9.1 is now in development and PostgreSQL 9.0 is slated for release soon.

As a general rule, the PostGIS Project Steering committee tries to maintain support of PostGIS for at least two versions of PostgreSQL. We sometimes support more than 2 PostgreSQL versions, if requirements do not necessitate bumping up requirement without too much effort.

We don't currently support 64-bit PostgreSQL Windows (which was introduced in PostgreSQL 9.0+).

Versions of GEOS support for PostGIS

The below chart shows which versions of GEOS work with which versions of PostGIS. The none means that you can get that version to work without GEOS, though its not recommended since a lot of functions will not be installed.

For the not recommended, this means that while you can get PostGIS to work with those versions, you'll be missing out on some PostGIS functions such as ST_Covers, ST_CoversBy and for PostGIS 1.5 the ST_HausdorffDistance and enhancements to ST_Buffer (both speed and functionality). GEOS 3.1 brought cascade union. GEOS 3.2 brought faster buffering and buffering enhancements, plus numerous enhancements with dealing with tolerance issues when unioning.

Geos Version	PostGIS 1.3	PostGIS 1.4	PostGIS 1.5	PostGIS 2.0
None	Yes (not recommended)	No	No	No
2.2	Yes (not recommended)	No	No	No
3.0	Yes	Yes (not recommended)	No	No
3.1	Yes	Yes	Yes (not recommended) (requires 3.1.1+)	No
3.2	Yes	Yes	Yes	Yes (not recommended)
3.3	Yes	Yes	Yes	Yes