First, download decompression
https://sourceforge.net/projects/freemarker-ide/files/
Copy the folder hudson.freemarker_ide_0.9.14 to the plugins of the Eclipse installation directory
Second, on-line installation
Tools to support syntax highlighting, syntax checking, code hints
Freemarker IDE (JBoss):
http://download.jboss.org/jbosstools/updates/development/
Installation method:
Eclipse--> help--> Install New Software--> Add--> name=freemarker,location=http://download.jboss.org/ jbosstools/updates/development/
MyEclipse--> help--> Software Updates--> Find and Install--> Search for new features to Install--> ADD --> name=freemarker,location=http://download.jboss.org/jbosstools/updates/development/
Simply select the "Freemarker IDE" under "JBoss TOOLS-3.1.0.V200912250601M-H198-CR1" to save installation time by not downloading other tools.