Language Localisation
Localization(l10n) helps in providing any application in native languages other than English which is default for many FOSS applications. Localization is more than mere translation where the application is localized understanding the locale and culture of the native language. Pootle and Translatewiki are some of the commonly used FOSS platforms for localizations. Each organization/applications use their own instance of these platforms to localize their software. Have listed some of them below sections.
Commonly used Applications
LibreOffice
Lireboffice is shipped as a default office application in most of the GNU/Linux distro. LO hosts their own instance of Pootle at - https://translations.documentfoundation.org/ and thanks to the community localizers, more than 80% of strings are already translated to Kannada - https://translations.documentfoundation.org/kn/
Mozilla
Firefox and Thunderbird are also commonly used FOSS applications for Internet browsing and Mail. They are currently being localized in at Mozilla Pontoon - https://pontoon.mozilla.org/. Firefox for Kannada is more than 85% localized but Thunderbird needs some love for Kannada since its not yet even available to localize!
Freeplane
Freeplane is a free and open source software application that helps you create and edit concept maps. Localisation of freeplane is hosted on Weblate - https://hosted.weblate.org/projects/freeplane/. All the non localised strings can be downloaded from this link for localising it on a spreadsheet - https://docs.google.com/spreadsheets/d/13HVCkuOUjeZ3ZnTZmdcldQNVhtxQx1sL9LML3nfoCEY/edit?usp=sharing
Gnome
Gnome session fallback is the default desktop environment we use in our Kalpavriksha and all the gnome applications from Calculator to System settings are localized at gnome's own localization platform - https://l10n.gnome.org/. Status of Kannada isn't much good with respect to most gnome applications - https://l10n.gnome.org/teams/kn/
KDE
Although we don't use KDE as our desktop environment, KDE loves kids and education, so we see many educational applications(all those starting with K - Kgeograpy, Kstars, Kalzium, etc.,.) in Kalpavriksha. All these applications are localized in KDE's own localization platoform at - http://l10n.kde.org/
Mediawiki
We use mediawiki extensively for hosting educational resources and its localization is currently done at Translatewiki
Other FOSS Applications
Other Applications like VLC are being translated at Transifex which is a proprietary platform for localization.
Desktop Applications for localization
Before the advent of web localization platforms(and even after), most of the applications were localized using desktop localization applications and then pushed to application repositories. Some of these commonly used applications are Poedit and Localize. Localize can also be used translate odt documents. OmegaT is another translation tool which supports many document formats like odt, doc, docx, html, wiki, etc.,. keeping the format and syntax of the document intact.
FUEL - Frequently Used Entries in Localistion
Fuel project emphasizes on setting a definite terminology standard so that the words used in translations remain correct and consistent preserving the sanctity of the context. Existing terminologies can be looked up here for most of the indic languages - http://fuelproject.org/contribute/index.php?route=search