If you're running the Notes 8.0x client and you don't see much benefit from the full Java framework in the full Notes 8 client, executing nlnotes.exe rather than notes.exe can be the difference between reasonable performance and not, depending on your PC's hardware configuration (e.g., if you have less than two gigabytes of RAM...); nlnotes.exe launches the "basic" Notes 8 client
What is the difference in function between the two executable files, Notes.exe and Nlnotes.exe? Both of these files are located in the Notes program directory.
Source: IBM - What is the difference between Notes.exe and Nlnotes.exe?