Here is my list of the top five gotchas when learning Windows PowerShell.
5. PowerShell will not run scripts by default.
4. PowerShell requires
. to run a script in the current directory.
3. PowerShell uses
-gt, etc. for comparison operators.
2. PowerShell uses backquote as the escape character.
1. PowerShell separates function arguments with spaces, not commas.
See PowerShell gotchas for more details and an explanation for why PowerShell made the design decisions it did. As surprising as these features are, there are good reasons for each.