Listing Loaded/Installed Package Versions List version numbers of loaded or installed packages.
package.version(all.available = FALSE, lib.loc = NULL)logical, if TRUE return all available packages.
character vector describing the location of R library trees
to search through, or NULL. The default value of NULL 
corresponds to all libraries currently known.
A list with components
names of loaded or available packages 
    if all.available is TRUE.
associated package versions.
This is a revised version of the base R function
  .package. It gives both package names and their version numbers.