I installed both libchewing and chewing on my Slackware64 14.2.
https://slackbuilds.org/repository/1.../scim-chewing/
The SCIM seems to have identified the installed chewing input method as it shows up a new menu "Chewing" in the IMEngine in the SCIM setup. (I run SCIM on KDE by the way) However, there was never a choice for me to put Chewing in the input selection menu. I wonder how I could add it into the menu.