There is no official repository for Aptana in Ubuntu, so some manual steps are required in order to get Aptana to work. There is also a weird Unity menu display issue, fortunately this can be worked around by the custom desktop launcher created below.

Installation

Visit http://www.aptana.com/downloads/start and download the latest zip file of Aptana

Or use wget (current as of time of writing)

wget -P ~/Downloads http://download.aptana.com/studio3/standalone/3.2.2/linux/Aptana_Studio_3_Setup_Linux_x86_64_3.2.2.zip

Unzip Aptana to /opt/aptana

sudo unzip ~/Downloads/Aptana_Studio_3_Setup_Linux* -d /opt -q sudo mv /opt/Aptana_Studio_3/ /opt/aptana/

Make sure you own it correctly (so updates will work)

sudo chown -R $(whoami):$(whoami) /opt/aptana/

Create the custom desktop launcher

sudo vim /usr/share/applications/aptana.desktop

and insert the following text:

[Desktop Entry]
Encoding=UTF-8
Name=Aptana Studio 3
Comment=IDE for Rails, Python, PHP
Exec=/opt/aptana/AptanaStudio3
Icon=/opt/aptana/icon.xpm
Terminal=false
Type=Application
Categories=GNOME;Application;Development;
StartupNotify=true

Finishing touches

You should now be able to find it in the unity launcher

Pinning it to the unity bar is a good idea

Hope this helps you, get cracking with Aptana in Ubuntu.