What I like most is qtmib, sadly not directly available in apt, but you do get deb and rpm packages http://qtmib.sourceforge.net/
If you're looking to do set operations as well as browsing: tkmib. That definitely is in de apt repo. I don't really like it because the user interface is the ugliest thing known to man and it scales horribly.
https://www.manageengine.com/products/mibbrowser-free-tool/
What I like most is qtmib, sadly not directly available in apt, but you do get deb and rpm packages http://qtmib.sourceforge.net/
If you're looking to do set operations as well as browsing: tkmib. That definitely is in de apt repo. I don't really like it because the user interface is the ugliest thing known to man and it scales horribly.
I have qtmib, it's very simplified, no SET command. Tkmin is very cluttered. Actually, the SNMP tools choice for windows is much better.
If you want to have the best experience, download all cablelabs mibs(.cablelabs.com/MIBs/) and add them to your folder with mibs for netsnmp(http://net-snmp.sourceforge.net/wiki/index.php/TUT:Using_and_loading_MIBS). Makes a lot of difference in convenience!
Here is another Tcl-MIBBrowser I find, looks much better than other front ends for Net-SNMP.
Tcl-MIBBrowser
Quick guide