The great thing about Vienna is its Kosher infrastructure. The the Kosher authorities in Vienna have taken great care to categorize many product on store shelves in the Kosher list. Luckily, you have the list at your fingertips here.
This is the main list from the Jewish Community of Austria, approved by Rabbi Schwartz.
Kashrus Committee Vienna HaMadrich
Here is the list for the Mizrachi Community:
Mizrachi Kosher Guide
Vienna also has a Kosher, fully-functional Eruv (עירוב) encompassing significant swaths of the central districts. Here is more information about it and the website will provide up-to-date information!
Kosher Dining in Vienna
Vienna has come a long way in the last 70-odd years. It offers an extensive selection of Kosher and Jewish-themed dining experiences. It has many Kosher grocery stores, restaurants, caterers and much more. ShabbesKitchen offers an excellent selection of Kosher options at their cozy eatery a few steps from Vienna’s Stadpark where the “gold-plated” statues of Strauss (Walz) stands. Shabbeskitchen offers catering Europewide from their Vienna location, and of course, on any trip in and around Vienna. Another excellent establishment, Shefa, offers a dairy cafe and a full-fledged grocery store. So whether Jewish-themed or strictly Kosher, Vienna’s infrastructure offers everything for everyone’s tastebuds.