I decided to use Piwigo, a freely available photo gallery web application, for setting up my photo gallery. Reason is that Piwigo is actively developed, has free themes and plugins available and best of al it is free. You can install Piwigo on your own server (for example on a QNAP nas) or at a hosting provider. Best thing is that I can publish my photos from Adobe Lightroom towards my Piwigo site easily, including all the metadata.
