Suggestions for splines
The following packages have something in common with the package splines. The packages are ordered in decreasing similarity.
- fiziko: A METAPOST library for physics textbook illustrations
 - mp-geom2d: Flat geometry with METAPOST
 - byrne: This package provides a set of tools to typeset geometric proofs in the style of Oliver Byrne's 1847 ed. of Euclid's “Elements”
 - roundrect: METAPOST macros for highly configurable rounded rectangles (optionally with text)
 - repere: METAPOST macros for secondary school mathematics teachers
 - huffman: Drawing binary Huffman trees with METAPOST and METAOBJ
 - mp-neuralnetwork: Drawing artificial neural networks with METAPOST and METAOBJ
 - mpchess: Drawing chess boards and positions with METAPOST
 - mptrees: Probability trees with METAPOST
 - bpolynomial: Drawing polynomial functions of up to order 3
 - cmarrows: METAPOST arrows and braces in the Computer Modern style
 - epsincl: Include EPS in METAPOST figures
 - hatching: METAPOST macros for hatching interior of closed paths
 - interpol: Add interpolation to METAPOST graph package
 - metaobj: METAPOST package providing high-level objects
 - mpattern: Patterns in METAPOST
 - metapost-matlab: METAPOST data plotting in Matlab style
 - txp: Draw text along a path
 - textpath: Setting text along a path with METAPOST
 - threeddice: Create images of dice with one, two, or three faces showing, using METAPOST
 - exteps: Include EPS figures in METAPOST
 - latexmp: Interface for LaTeX-based typesetting in METAPOST
 - featpost: METAPOST macros for 3D
 - metapost-colorbrewer: An implementation of the colorbrewer2.org colours for METAPOST
 - automata: Finite state machines, graphs and trees in METAPOST
 - shapes: Draw polygons, reentrant stars, and fractions in circles with METAPOST
 - blockdraw_mp: Block diagrams and bond graphs, with METAPOST
 - dviincl: Include a DVI page into METAPOST output
 - drv: Derivation trees with METAPOST
 - mparrows: METAPOST module with different types of arrow heads
 - makecirc: A METAPOST library for drawing electrical circuit diagrams