ktikz (also available in the
qtikz version), which seems not only run on Linux/KDE but also on Windows.
Version 0.10 is released. This version is available as an Ubuntu package for Lucid, as a Debian package for Squeeze and as a Windows installer (a patch release 0.10.1 is available). For Linux there are two versions available: KtikZ and QtikZ. KtikZ is integrated with the KDE4 platform, whereas QtikZ has the traditional Qt-only interface.
I personally use
latexmk -pdf -pvc to keep recompiling my TikZ diagram file after every saved edit. I use a dedicated file for every diagram which uses the
standalone class (which I wrote just for this very purpose). If you use a PDF viewer with auto-reload like
evince then the changes are shown directly (after each save). I had issues getting
latexmk reloading PDFs in the Adobe Reader.