Though it’s not vocal music, it is music by an incredibly prolific and wonderful composer of vocal music, and I think a great decision on the part of a publisher to reach out electronically:
Universal Edition has put online the scores to each of Wolfgang Rihm’s string quartets, celebrating their performance at the 5e Biennale de quatuor à cordes. It’s a wonderful opportunity to peruse these scores at your leisure, without leaving the comfort of your desk!