There seems to be no Debian packages for XOTcl. The installation instruction of XOTcl mentioned TCL sources are a must. Many people will put-off installation because of these points.
Things are not that complex.Here is a instruction to get it going.
Actually TCL headers are required, not full source files.
Debian packages required - tcl package and tcl-dev package. tcl-dev is required if you want any C based extension for Tcl.
In my case,
apt-get install tcl8.4 apt-get install tcl8.4-dev
The required packages for compiling C code (someone mention that. I assume they are present).
Get the source code from xotcl website.
let us say you had downloaded xotcl_xx.tar.gz to '/var/downloads'
cd /var/downloads . tar xvzf xotcl_xx.tar.gz
cd /var/downloads/xotclxxx ./configure --with-actiweb --with-tcl=/usr/lib/tcl8.4 make
Now you will have libxotclxxx.so in /var/downloads/xotclxxx
Now copy that (*.so) into you desired directory and play with xotcl. tclsh load ./libxotclxxx.so namespace import xotcl::* object junk junk destroy
for more info xotcl for prototying