+: **is4()**
+Returns true, if zsh version is equal or greater than 4, else false.
+
+: **is41()**
+Returns true, if zsh version is equal or greater than 4.1, else false.
+
+: **is42()**
+Returns true, if zsh version is equal or greater than 4.2, else false.
+
+: **is425()**
+Returns true, if zsh version is equal or greater than 4.2.5, else false.
+
+: **is43()**
+Returns true, if zsh version is equal or greater than 4.3, else false.
+
+: **is433()**
+Returns true, if zsh version is equal or greater than 4.3.3, else false.
+
+: **isdarwin()**
+Returns true, if running on darwin, else false.
+
+: **isgrml()**
+Returns true, if running on a grml system, else false.
+
+: **isgrmlcd()**
+Returns true, if running on a grml system from a live cd, else false.
+
+: **isgrmlsmall()**
+Returns true, if run on grml-small, else false.
+
+: **isutfenv()**
+Returns true, if run within an utf environment, else false.
+
+: **limg()**
+Lists images (i. e. files ending with ".jpg", ".gif" or ".png") in current
+directory.
+