I'm using Libgdx to write an Android and HTML5 app. I have found out that FreeTypeFontGenerator doesn't work for a GWT application and truetype is deprecated. What shall I use if I want to use fonts in a GWT application?
You use BitmapFont just like you do in any LibGDX application, it is the standard mechanism to support fonts in LibGDX. FreeTypeFontGenerator is an extension that doesn't work for GWT because it features native code. If you need to pre-generate some new font files of different sizes and types you can use Hiero or my favorite BMFont.