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What are the best open-source map/hash-table libraries for C?

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UTHash vs Judy Arrays vs Klib

 vs Libcfu's cfuhash vs SunriseDD (Sunrise Data Dictionary for C) vs Hashit vs CMPH - C Minimal Perfect Hashing Library vs GLib's GHashTable vs TommyDS vs libghthash

Pros + Cons

Pro
 BSD license

UTHash is released under the BSD license, which allows its redistribution even for commercial use.
Comment

Pro
 Well documented

UTHash documentation is detailed, well organized and uses plenty of examples.
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Pro
 Easy to use

UTHash is straight forward to use and is easy to install.
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Con
 Not the fastest/slimmest option

There are other options which either show better performance characteristics or better memory usage (as in overhead per item), or sometimes both. Specific comparison micro benchmarks including plots for the data can be found here.
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Con
 Lacks some basic API methods

For example, it doesn't have a method for counting the number of elements in a hash table.
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Con
 No longer maintained

This notice is posted in the documentation: "As of 2015 uthash is unmaintained software."
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Pro
 Memory efficient

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Pro
 Very cache-friendly when accessing things in order

Judy is pretty good at inserting and looking up keys in order. This makes Judy probably unbeatably the best when it comes to being cache-friendly.
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Con
 Slow for random access and sparse keys

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Pro
 Strong documentation

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Pro
 Simple to use

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Pro
 Easy to modify

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Pro
 Well-documented source code

SunriseDD's source code is very well documented.
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Pro
 Implements a lock-free hash table

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Con
 Support for only static hash tables

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Pro
 Very fast

GLib's GHashTable is one of the fastest overall of the open source implementations you can benchmark. It has low memory use as well.
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Con
 Only has support for 32-bit

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Pro
 Actively developed

TommyDS is actively developed by the creator.
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Con
 Poorly formatted documentation

The documentation is poorly organized, and requires some searching before finding what you're looking for. The styling used to display the explanations can be hard on the eyes.
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