Attempto Parsing Engine (APE)
The source code of the Attempto Parsing Engine (APE) plus some related tools is available under the GNU Lesser General Public License, on GitHub:
APE is written in Prolog,
In order to use APE, you must install SWI-Prolog and its packages
Recent versions of SWI-Prolog (5.6.57 and higher) should be OK.
SWI-Prolog is available in a pre-compiled form for Windows, Mac OS X
and many Linux distributions.
There is an easy-to-use command-line tool
which provides an interface to APE and
the other modules. For example, executing:
./ape.exe -text "Every man is a human." -solo drsxml
will output the DRS of the ACE sentence "Every man is a human." in XML.
To compile this command-line tool, just execute
make_exe.bat, if you are using Windows).
APE also comes with a Java interface.
Furthermore, there is a content words lexicon with ~100,000 entries under
the GNU General Public License.
AceWiki and the ACE Editor are hosted on GitHub too:
Previously, AceWiki was hosted on Launchpad:
Older versions can be downloaded here: