Package versions:
Tcl           --  8.6.6
Tcllib json   --  1.3.3
jimhttp json  --  2.1.0
sqlite3       --  3.16.2
jsonDecode    --  Tcler's wiki
ton           --  0.1

Running test 'RFC 7158 example object' with 1000 iterations for each library
SQLite JSON1            7.61 μs/run
json2dict              30.80 μs/run
ton2list              379.10 μs/run
ton2dict              382.81 μs/run
tona2dict             375.52 μs/run
Tcllib JSON           418.01 μs/run
jsonDecode            864.98 μs/run
jimhttp JSON         2074.32 μs/run

Running test 'Mockaroo with 100 items' with 250 iterations for each library
SQLite JSON1            0.05 ms/run
json2dict               0.58 ms/run
ton2list               16.50 ms/run
ton2dict               16.37 ms/run
tona2dict              16.39 ms/run
Tcllib JSON            23.37 ms/run
jsonDecode             46.05 ms/run
jimhttp JSON           38.40 ms/run

Running test 'Mockaroo with 1000 items' with 50 iterations for each library
SQLite JSON1            0.41 ms/run
json2dict               5.82 ms/run
ton2list              168.37 ms/run
ton2dict              167.31 ms/run
tona2dict             167.66 ms/run
Tcllib JSON           241.14 ms/run
jsonDecode            463.61 ms/run
jimhttp JSON          389.61 ms/run

Running test 'json-generator.com repeat(10000, 100)' with 3 iterations for each library
SQLite JSON1            0.02 s/run
json2dict               0.23 s/run
ton2list                4.14 s/run
ton2dict                4.15 s/run
tona2dict               4.19 s/run
Tcllib JSON             4.99 s/run
jsonDecode              9.38 s/run
jimhttp JSON           17.47 s/run

Running test 'Magic The Game Card Data' with 2 iterations for each library
SQLite JSON1            0.13 s/run
json2dict               1.20 s/run
ton2list               24.55 s/run
ton2dict               24.48 s/run
tona2dict              24.60 s/run
Tcllib JSON            27.69 s/run
jsonDecode             52.10 s/run
jimhttp JSON          121.73 s/run