Well if there's no packaged binary for your distro you can try building the package from source. Get the gzipped tarball and extract it somewhere you do your build-related stuff, and follow the standard procedure:
$ cd ~/build
$ tar xzf amsn-0.98.4-src.tar.gz
$ cd amsn-0.98.4
Here you make sure to read all important files, such as `README`, `INSTALL` and `HELP` before continuing. Then you compile and install:
$ ./configure
$ make
# make install
**Note** : on `SL 6.1 64bit` you will need this before the install:
# yum install gcc-c++ tcl-devel tk-devel libpng-devel libjpeg-devel gstreamer-devel farsight2-devel -y