Suggestions for rviewport
The following packages have something in common with the package rviewport. The packages are ordered in decreasing similarity.
- graphbox: Extend graphicx to improve placement of graphics
 - graphicxbox: Insert a graphical image as a background
 - grfpaste: Include fragments of a dvi file
 - graphfig: Simpler graphic, subfigure and float
 - nccpic: Extend the graphicx package for more formats
 - graphicxsp: An extension of the graphicx package
 - swfigure: Insert large images that do not fit into a single page
 - pdfoverlay: A LaTeX style for overlaying text on a PDF
 - graphicx-psmin: Reduce size of PostScript files by not repeating images
 - graphicxpsd: Adobe Photoshop Data format (PSD) support for graphicx package
 - incgraph: Sophisticated graphics inclusion in a PDF document
 - inlinegraphicx: Insert inline images, with automatic size/positioning
 - realhats: Put real hats on symbols instead of ^
 - longfigure: Provides a figure-like environment that break over pages
 - pdfreview: Annotate PDF files with margin notes
 - fadingimage: Add full width fading pictures at the top or bottom of a page
 - pdfpages: Include PDF documents in LaTeX
 - epsfig: Include Encapsulated PostScript in LaTeX documents
 - graphics: Standard LaTeX graphics
 - graphicx: Enhanced support for graphics
 - graphicp: An enhanced version of graphics
 - epsf: Simple macros for EPS inclusion
 - psbox: PostScript box macros, etc.
 - domaincoloring: Draw colored represenations of complex functions
 - pst-graphicx: A PSTricks-compatible graphicx for use with Plain TeX
 - graphics-pln: LaTeX-style graphics for Plain TeX users
 - epsfx: A TeX macro package for including EPS graphics
 - fig4latex: Management of figures for large LaTeX documents
 - psfig: A graphics inclusion package
 - mma2ltx: Use Mathematica graphics in a LaTeX document
 - latexscreenshooter: Capture screenshots within LaTeX documents