Please see this comment #474 (comment) for the current state of this project.
Nifty is available in the Maven central:
<groupId>com.github.nifty-gui</groupId>
<artifactId>nifty</artifactId>
<version>1.4.3</version>To use SNAPSHOT builds of Nifty you'll still need to add the Sonatype snapshots repositories to your pom.xml.
<repositories>
<!-- only needed for snapshot builds starting with 1.4.4-SNAPSHOT -->
<repository>
<id>ossrh</id>
<url>https://oss.sonatype.org/content/repositories/snapshots/</url>
</repository>
</repositories>
