Yes, they are brand names of laminated veneer lumber (LVL) used for very strong beams.
Versa-Lam LVLs are made by Boise Cascade.
Microllam LVLs are made by Weyerhauser

The important thing to look for is that the strength rating is the same as specified by your engineer.

Weyehauser uses different names for their other composite/laminated lumber materials:
- TimberStrand is Weyerhauser's laminated strand lumber (LSL) used mostly for rim boards.
- Parallam is Weyerhauser's parallel strand lumber (PSL) used mostly for columns.

Boise-Cascade uses the Versa-Lam name for most of its composite wood products so there is a
- Versa-Lam LSL rim board and a
- Versa-Lam PSL column.

A proposal that only uses the brand names without the generic letter designations would be a sloppy one IMO.

A structure using composite/laminated lumber materials should be designed by an engineer whether the engineer works for you or the lumber manufacturer and the proposals should be reviewed by the engineer of record.

This post was edited by Renovator8 on Mon, Sep 15, 14 at 8:40