How to setup plugin system in Koha

Koha plugins allow users to add additional tools/features.

We have to make some changes in Koha installation.

Follow the steps to get ready Koha to facilitate plugins,

Open a Terminal and execute following commands,

Create a directory for plugins,

sudo su
mkdir /var/lib/koha/plugins
cd /var/lib/koha
chmod -R 755 plugins

Open the following file using your default text editor (e.g. gedit, leafpad)

sudo leafpad /etc/koha/sites/library/koha-conf.xml

Go to the bottom of the file and add the following line before </config>

<pluginsdir>/var/lib/koha/plugins</pluginsdir>
<enable_plugins>1</enable_plugins>

Save and close the file. 

Open Apache configuration file for Koha,

sudo leafpad /etc/apache2/sites-available/library.conf
 
Add the following line  at the bottom of the file,

Alias /plugin/ "/var/lib/koha/plugins/"

Save and close the file.

Restart Apache,

/etc/init.d/apache2 restart

Start Koha and goto,

Administration > System Preferences > Enhanced content > Plugins > UseKohaPlugins > Enable

Save preferences.

Goto Koha > Tools > Tool Plugins

You can upload and run plugins from here.
Please find few Koha plugins from the following link,
http://bywatersolutions.com/koha-plugins/ 

Reference
http://manual.koha-community.org/3.12/en/pluginsystem.html