Here is a test of OpenType features in Junicode. First, whether the lang attribute has an effect. Here is a passage of Old English, using the default letter-shapes:

Her geendode    eorðan dreamas
Eadgar, Engla cyning,    ceas him oðer leoht,
wlitig and wynsum,    and þis wace forlet,
lif þis læne.    Nemnað leoda bearn,
men on moldan,    þæne monað gehwær
in ðisse eðeltyrf,    þa þe ær wæran
on rimcræfte    rihte getogene,
Iulius monoð,    þær se geonga gewat
on þone eahteðan dæg    Eadgar of life,
beorna beahgyfa.    Feng his bearn syððan
to cynerice,    cild unweaxen,
eorla ealdor,    þam wæs Eadweard nama.

Now a short stretch of Old Icelandic (Hávamál) clipped from the web (somewhere). We get Icelandic letter-shapes (in Firefox anyway) by adding the tag lang="is" to an enclosing element.

textimage
Gáttir allar,
áðr gangi fram,
um skoðask skyli,
um skyggnast skyli,
því at óvíst er at vita,
hvar óvinir
sitja á fleti fyrir.

Gefendr heilir!
Gestr er inn kominn,
hvar skal sitja sjá?
Mjǫk er bráðr,
sá er á brǫndum skal
síns of freista frama.
what it should look like

Now for something a little more exotic. We'll try the Old English passage from above, but substituting insular letter-shapes using the OpenType tag ss02. If you look at the page source you'll see that the underlying text is exactly the same:

textimage
Her geendode    eorðan dreamas
Eadgar, Engla cyning,    ceas him oðer leoht,
wlitig and wynsum,    and þis wace forlet,
lif þis læne.    Nemnað leoda bearn,
men on moldan,    þæne monað gehwær
in ðisse eðeltyrf,    þa þe ær wæran
on rimcræfte    rihte getogene,
Iulius monoð,    þær se geonga gewat
on þone eahteðan dæg    Eadgar of life,
beorna beahgyfa.    Feng his bearn syððan
to cynerice,    cild unweaxen,
eorla ealdor,    þam wæs Eadweard nama.
what it should look like

Here are some other features, briefly (the OpenType feature tag employed is in parentheses):

textimage
  • True small caps (smcp): true small caps
  • Discretionary ligatures (dlig): strict
  • Historical forms (hist): session
  • Historical ligatures (hlig): are medievalist may egg track
  • Old-Style numbers (onum): 123456780
  • Enlarged minuscules (ss06): enlarged minuscules
  • Roman numbers with high overline (ss04): MMXII
  • Roman numbers with low overline (ss05): mmxii
  • Underdotted text (ss07): Delete this text
  • Runes: ᚻᚱᚩᚾᚫᛋᛒᚪᚾ
  • Runes mirrored right to left (rtlm): ᚻᚱᚩᚾᚫᛋᛒᚪᚾ
what it should look like

By the way, if you look at the source for the last two lines, you'll see that the runes actually occur in the same order but are displayed in reverse. Look at the source for the CSS for this cool trick, which I found blogged at http://www.navarinounincorporated.com/. The CSS reverses the order of the letters and the OpenType feature reverses each letter.