Poedit is a gettext catalogs editor, also known as .po files. It is built with the wxWidgets toolkit and can be run on your *buntu distribution. It was created to make an easier and more convenient way to edit catalogs. It is often used in translation work, and can be a very useful tool to use. Poedit is licensed under the MITS license.
To install Poedit,
sudo apt-get install poedit
This will automatically download and install the required dependencies as well.
Poedit can be launched from the Unity and GNOME desktops by searching for poedit on the Dash/Activities view’s search bar, from the terminal with the command poedit &, or from the MATE desktop through Applications ▸ Programming ▸ Poedit.
On the first run you are asked to enter your name and email address, this is (as explained) to add your details as a contributor to the headers of the .po file. You can also select or deselect other options on the settings tabs. Most of the time though you won't need more than just entering your name and email.
You will need to gain your .po file from what ever community or resource you are helping out. Open up the catalog file with poEdit and you will be presented with the main screen. At the top you will see all the strings that need translated. To start translating just click on one. In the box below it will show the translation in the original string language. In the editBox below that you must now enter the translation.
If your translation of a string is only a guess you can submit but mark as fuzzy, meaning other translators can see that you are unsure. To mark as fuzzy click the question mark like icon on the bar, when you are selected on the string in question.
You may also want to add a comment that other translators can see. To do this just click on the notepad icon, and add your comment.
Figure 1: Default poEdit screen layout
Poedit and Launchpad
An example (and how I use it) is to download .po files from the Launchpad website. This is a resource for many tasks within the *buntu communities. One section called Rosetta is aimed at helping translations. Once you have joined a team you can download a catalog of a section. To do this click on a program to translate, then on the left hand column click Download, confirm your email address and make sure it is exported as PO export. You will be emailed confirmation and a link to the download.
Poedit comes with a help file provided and can be acced by hitting F1. You could also check out the sites Support page.