Here is a list of most of the features. You can combine all of them for the ultimate DAU experience. Look in the alias section for examples.

boxes
[Put] [every] [word] [in] [a] [box]
bracket
--==||{{ Put text in neat brackets }}||==--
chars
Every character in a new line
color
Write in colors
cool
Be cool[tm] (-:
cowsay
Use cowsay to write text
delimiter
Put a string of your choice between characters
dots
Dots ..... between ... words......
figlet
Use figlet to write text
leet
pH34r M3 |M 4 H4x0R
mix
Mix all the caetcrrahs in a wrod epecxt for the fsirt and lsat
mixedcase
wRItE in miXedCASe
moron
WRIET LOKE THIS ????!!!!????!!??????????!!!!11111
stutter
Stutter eeeh, a, a, a bit
underline
Underline text
uppercase
WRITE IN UPPERCASE
words
in
every line
only
a few
words

Remember: You can combine all these options! So it is possible to write in uppercase, in colors and underline the text, for example. There are much more IRC specific features included. Check /dau --long_help.