Hi, friends. We love open-source and and we are free to speak. I have listed some open-source softwares below.

1. Firefox: Firefox is the top browser running on all the system/PC developed by the company Mozilla. Talking about Firefox, they are open-source and free, so they can be easily distributed to anyone by any means. The biggest feature about this browser is they have the biggest team of developer making it large. It has Add-ons facilities making it more flexible.
2. Thunderbird: Thunderbird is a mail client software which runs on every PC/system making it cross-platform.
3. Filezilla: Filezilla is the best open-source FTP client software which is used world wide.
4. Pidgin: Pidgin is the IM software enabling most of all the Social Chatting.
5. Geany: Geany is the open-source editor, which can be used to write a normal text document to a large projects for coding.
6. GIMP: GIMP(GNU Image Manipulation Program) is the biggest open-source photo editing software. Its really easy and can support all the formats of file.
7. Tomboy: I love keeping notes and when I don’t have any pen and paper nearby I only rely on Tomboy. It is the biggest open-source quick note making software.
8. VLC: Supporting most of the video and audio file to open enables VLC becoming the biggest open-source player right now.
9. Code::Blocks IDE: I love programming and while using this software, I am always happy to have my code look professional. Thanks to Code::Blocks.
10. Libre Office: Well after a long success of OpenOffice.org, the biggest open-source software in competition is Libre Office helping managing every documents and presentations.

There are other open-source softwares that must have been in the list but I stated only the top 10 so these were the top 10 open source softwares of the year. If there were more, I would surely keep OpenOffice.org, Assault Cube, NetBeans, empathy and more.
Also talking about OS the best OS that I love is Ubuntu.
Enjoy the freedom.