How to Install Sublime Text 2 or 3 in Ubuntu 15.04

Sublime Text is a cross-platform text and source code editor with a Python API. It is a sophisticated text editor for code, markup and prose. Its functionality is extendable with plugins. Most of the extending packages have free-software licenses and are community-built and maintained.
Sublime Text features:

• “Goto Anything,” quick navigation to files, symbols, or lines
• “Command palette” uses adaptive matching for quick keyboard invocation of arbitrary commands
• Simultaneous editing: simultaneously make the same interactive changes to multiple selected areas
• Python-based plugin API
• Project-specific preferences
• Extensive customizability via JSON settings files, including project-specific and platform-specific settings
• Cross platform (Windows, OS X, Linux)
• Compatible with many language grammars from Textmate.
• proprietary software, may be downloaded and evaluated for free, however a license must be purchased for continued use.

Install Sublime Text 2 in Ubuntu:

Thanks to Webupd8 Team, an installer script has been made into PPA that automatically downloads Sublime Text 2 from its website and installs it and its launcher, docs on your Ubuntu.
To add the PPA, open terminal from Dash/Menu or by pressing Ctrl+Alt+T on keyboard. When it opens, run:

sudo add-apt-repository -y ppa:webupd8team/sublime-text-2

After adding the PPA, you can install the text editor via Synaptic Package Manager (install it from Software Center) by doing below steps:

• Launchpad Synaptic package manager and click Reload button.
• Search sublime-text in the filter box.
• right-click on sublime-text and select “mark for installation”.
• finally click Apply button.

Once installed, launch the editor from the Dash/Menu.

Install Sublime Text 3 Beta in Ubuntu:

Similar to above instructions, run below command instead to add another PPA and finally install the editor via Synaptic package manager.

sudo add-apt-repository -y ppa:webupd8team/sublime-text-3

NOTE: you can only install one version of Sublime Text in your Ubuntu. To install version 3, you may first remove version 2 from Synaptic package manager