Specialties

Fig. 1: The versal Eszett
Fig. 2: Double-consonant ligatures
Fig. 3: Kerning
Fig. 4: Scientific glyphs (klick to enlarge)

The versal Eszett
For more than a century, typographers kept demanding the Eszett wide acceptance in the versal setting. Finally, the DIN-Institut (German Standarization) submitted a petition to the ISO, which derived, that in April 2008 the Versal Eszett was given a position in Unicode (at U+1E9E). Linux Libertine has itself developed a form at the basis of Andreas Stötzner’s proposal (Signa Nr.9). Two of them exist: a capital and a small capital form (see right figure). Further information can be found at Wikipedia: Versal-Eszett.
Kerning
Kerning is standard in quality fonts, but how much time and effort the designer wants to spent is quite different. During the last years, the standard method was to define a one-by-one Kernpair table. Now OpenType fonts can offer a more elegant solution: a kern-by-classes table where groups of similar characters are seen as one kern group, i.e. V and W have nearly the same left and right geometry, and so are in the same kern group. Linux Libertine utilizes this feature, and therefore it may not be supported in simple or old software that it doesn’t understand GPOS kerning too well.
Double-consonants ligatures
The German language makes use of many doubled consonants, which often formerly had their own glyphs in the Fraktur. These doublekonsonants have in Linux Libertine their own ligatures again. The new German orthography has abolished the 3rd-Konsonant-diminution-rule, and so the German got some typographically ugly words (like Flussschifffahrt). The Doublekonsonant-ligatures of Libertine will make a better form. Additionally they help the reader to register the glyph group as having just one phonetic value. Another positive consequence is the more compact word presence and the shortening of the long German word chains.
Scientific characters
Especially in the natural sciences, special characters are often needed. In mathematics, for example, the Greek letters have long standing historical use as variables. In chemistry, one uses equilibrium arrows regularly, and biologists may need gender signs once in a while. Though you will still need a special editor to generate complex formulas, you can use Libertines scientific possibilities to set simple equations in running text.
Hinting (displaying on screen)
On optical devices, the resolution is often too bad to show glyphs in their full beauty. While printers, especially laser printers, nowadays reach 300dpi easily, PC-users still are stuck with their 75dpi monitors. Glyphs must therefore being rasterized. A complex technique, that is called “Hinting”, can be used to show glyphs clearly also at small sizes, while the glyphs metrics must be deformed to fit to the monitor’s pixels. The effect is a clearer view on screen, but the font looks temporarily different from the later printer-output. “Hinting” itself is so far no real “specialty”, because all good fonts do have it, but the font designer needs good knowledge and special software, to be professional in his “hinting”. Latest Linux-Systems often have a socalled Auto-Hinter, which makes it possible to see unhinted fonts on screen quite clear nontheless. Since version 2.7 Linux Libertine’s TTFs contain TrueType-Hinting for better rastering on Windows (see fig.) or Wikipedia: Hint.