Suggestions for Xr

The following packages have something in common with the package Xr. The packages are ordered in decreasing similarity.

Package varioref: Intelligent page references
Package showkeys: Show label, ref, cite and bib keys
Package indentfirst: Indent first paragraph after section header
Package upref: Ensure references are upright
Package totpages: Count pages in a document, and report last page number
Package array: Extending the array and tabular environments
Package afterpage: Execute command after the next page break
Package rawfonts: Low level font compatibility mode for LaTeX
Package somedefs: Save loading all of another package
Package shellesc: Unified shell escape interface for LaTeX
Package trace: Make sensible use of TeX tracing in LaTeX
Package xspace: Define commands that appear not to eat spaces
Package multicol: Intermix single and multiple columns
Package tabularx: Tabulars with adjustable-width columns
Package bm: Access bold symbols in maths mode
Package calc: Simple arithmetic in LaTeX commands
Package dcolumn: Align on the decimal point of numbers in tabular columns
Package delarray: Delimiters for arrays
Package fontsmpl: Print a sample of a font
Package ftnright: Footnotes in two column documents in one column only
Package hhline: Better horizontal lines in tabulars and arrays
Package longtable: Allow tables to flow over page boundaries
Package layout: View the layout of a document
Package theorem: Manipulate theorem environments
Package verbatim: Reimplementation of and extensions to LaTeX verbatim
Package enumerate: Lists with redefinable labels
Package showlabels: Show label commands in the margin
Package cite: Improved citation handling in LaTeX
Package overcite: Compressed lists of superscript numerical citations
Package listlbls: Creates a list of all labels used throughout a document
Package refcheck: Check references (in figures, table, equations, etc)