Instalação do balsamiq no Ubuntu 14.04

balsamiq

sudo apt-get install gnome-keyring gdebi gdebi-core

sudo apt-get install gtk2-engines:i386 libart-2.0-2:i386 libcairo2:i386 libcanberra-gtk0:i386 libdatrie1:i386 libgail-common:i386 libgconf2-4:i386 libgtk2.0-0:i386 liblua5.1-0:i386 libpango1.0-0:i386 libpixman-1-0:i386 libqt4-network:i386 libqt4-test:i386 libqtcore4:i386 libthai0:i386 libbonobo2-0:i386 libglade2-0:i386 libgnomecanvas2-0:i386 libidl0:i386 liborbit2:i386 libwmf0.2-7:i386 gtk2-engines-murrine:i386 libxml2:i386 libxslt1.1:i386 libxt6:i386 lib32nss-mdns libnspr4-0d:i386 libnss3-1d:i386

Now, download AdobeAIRInstaller.bin (http://airdownload.adobe.com/air/lin/download/2.6/AdobeAIRInstaller.bin) version 2.6 
and MockupsForDesktop64bit.deb (http://builds.balsamiq.com/b/mockups-desktop/MockupsForDesktop64bit.deb)

cd ~/Downloads
chmod +x AdobeAIRInstaller.bin # make Adobe AIR executable
LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu ./AdobeAIRInstaller.bin # install Adobe AIR

Once AIR is installed, open your file manager, right-click on the balsamiq package and choose open with -> gdebi. The install should now complete.