### 2.2 Build requirements

GNU tar is required to unpack PolyORB source packages.

Ada compiler:

- GNAT Pro 6.2.* or later
- GNAT GPL 2009 or later
- FSF GCC 4.4 or later

For builds for cross targets, both a native and a cross compiler are required, as some tools (like an IDL-to-Ada compiler) are meant for use on the build host.

A Python interpreter is required for installation.

Optional:

- (Only for older versions of GNAT, and only if you want to build the CORBA application personality): A C++ compiler. The OMG IDL specification mandates that IDL source files be preprocessed according to standard C++ preprocessing rules. Newer versions of GNAT provide an integrated IDL preprocessor. This feature is detected and used automatically. However, for older versions of GNAT, PolyORB relies on an external preprocessor provided by a suitable C++ compiler. Please refer to the documentation of your particular version of GNAT to know if it supports this feature.
- XML/Ada (http://libre.adacore.com/libre/tools/xmlada/) if you want to build the SOAP protocol personality.

Note: per construction, the macro `configure` used to find your GNAT compiler looks first for the executable `gnatgcc`, then `adagcc` and finally `gcc` to find out which Ada compiler to use. You should be very careful with your path and executables if you have multiple GNAT versions installed. See the explanation below on the ADA environment variable if you need to override the default guess.