no time to write a long post. this is one way to get rid of the plaintext passwords, using sasl when running a svn server on ubuntu or pretty much any debian-based distro. this assumes that you have svnserve up and running, also /svn/root means your svn root folder, not necessarily that path. the indented parts are supposed to be entered in files (here i use vim, you can change it to <your-editor-of-choice>).
sudo apt-get install libsasl2-2 libsasl2-modules sasl2-bin
sudo vim /etc/default/saslauthd
# change the row that says START=no to START=yes
cd /svn/root
sudo svnadmin create newrepo
sudo vim newrepo/conf/svnserve.conf
# insert the following
[general]
anon-access = none
auth-access = write
# realmname may not contain special chars (this includes spaces, dashes and pretty much anything except a through z)
realm = realmname
[sasl]
use-sasl = true
min-encryption = 256
max-encryption = 256
# EOF
sudo vim /usr/lib/sasl2/svn.conf
# this is the basic setup.. alotta settings can be used
pwcheck_method: auxprop
auxprop_plugin: sasldb
# i used /etc/svn_sasldb here
sasldb_path: /path/db_name
mech_list: DIGEST-MD5
# EOF
sudo ln -s /usr/lib/sasl2/svn.conf /usr/lib/sasl2/subversion.conf
# add as many users as you need
sudo saslpasswd2 -f /path/db_name -c -u realmname username
sudo /etc/init.d/svnserve restart
# and ya done!!
// sluggo