Organization related to open source:
(i)  Apache Software Foundation
(ii)  Free Software Foundation
(iii) Linux Foundation
(iv) Open Source Initiative.

Open NMS has three main functional areas:
(i) Services monitoring
(ii) Data Gathering
(iii) Event Management and notification
(i) Services monitoring:
A number of monitor modules can govern if network-based services are accessible (ICMP, HTTP, DNS, etc.).
(ii) Data Gathering:
Data Gathering by SNMP and JMX (Simple Network Management Protocol-SNMP, Java Management Extensions-JMX).
(iii) Event Management and notification:
It comprises of alarm reduction and a robust announcement system with acceleration and duty schedules.

(i) In this period of increased competition and cyber crimes, the computers used by indivudals or business organisations may have spy hardwares of rivals.
(ii) Open source hardware technology helps in such threats.
(iii) In this technique we get the components of the hardware and its circuit diagram, so that we can remove suspicious spyware if found.

NS2, OPEN NMS, Ubuntu, MySQL, PDF Creator, Open Office, 7zip GNUCASH, GIMP, BLENDER, AUDACITY, VLC, MOZILA FIREFOX, MAGENTO, ANDROID, PHP.

(i) Free software is a concept developed in the 1980s by an MIT computer science researcher, Richard Stallman who defined four conditions, as outlined by the nonprofit Free Software Foundation.
(ii) These "four freedoms" emphasize the ability of users to use and enjoy software as they see fit.
(iii) Freeware usually refers to proprietary software that users can download at no cost, but whose source code cannot be changed.

(i) Software can be used without any cost and restrictions
(ii) Sharing of ideas with the team.
(ii) User friendly.
(iv) We can add the most required features in the software.
(v) We can learn many ideas.
(vi) We can make our program writing skills more efficient