To download Notepad++ go to http://notepad-plus-plus.org/download/

Here the Notepad++ User Defined Language files for:

• ASN.1 (e.g. MIB files)
• Castle Rock SNMPc Filers (in a MIB file)
• HP OpenView NNM Trapd Filters (trapd.conf)
• IBM Tivoli SnmpProbe NCKL Rules v.3

To use this rules import them from a file.

1. Choose the mrnu item "Language".
2. And click the item "Define your language...".
3. Push "Import" button.
4. Choose UDL (*.xml) file, e.g. ASN.1.UDL.npp.xml.
5. Take a look at dropbox named "User Language:" for the new item.

Try to open a file and take a look at a syntax highlight.