The graphical interface of Klavaro is based on other program called "GTK+ 2" (not really a program, but a set of libraries). It's absolutely necessary that it is correctly installed on your system.
At Linux, under a configured X graphical system, probably you are using other programs based on GTK. That is, this toolkit is to be already installed.
On Windows, you don't have to worry about this, because the provided binary already contains all that stuff. That's why it's so big...
In order to use the program as a "semi-online" game, you need to have installed in your system this library: 'libcurl3'. It's widely available only for Linux based systems, so, there are little chances to get that working on Windows.
For Debian based distributions, a very quick way to install that library is through the command line:
apt-get install libcurl3
Obviously, that must be done as "root" (administrator). Or, you may prefer to install from other package managers, with graphical interfaces, such as "aptitude", "kpackage", etc.
The last version of the manual (1.0.8) is not translated to English. For now, there are only the Portuguese and Esperanto versions.
If you want to help this project on translating its documentation to English, see this source file, it uses LaTeX: klavaro-dok-1.0.8.tar.gz (183 kB). Then, you are supposed to translate from Portuguese or Esperanto, of course.
May be very useful an article about Klavaro, in the site Penguin Sightings. It's nicely written, the description is very actual.
If you want to give us some feedback, sugestion, ask for help, support or any thing else, please visit the forums at SourceForge. There you will find rooms for English, Esperanto, Hungarian and Portuguese.
Be aware that in order to post there, you must have an account at SourceForge. That's to avoid spamming from anonymous people. If you still aren't registered, spend some minutes first to do it: create an account at SourceForge.
All right, go to: Klavaro - Forums