APRIORI algorithm was originally proposed by Agrawal in "Fast Algorithms for Mining Association Rules" in 1994 to find frequent itemsets and association rules in a transaction database. Here you can download a fast, trie-based, command-line implementation
Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or called from your own Java code. Weka contains tools for data pre-processing, classification, regression, clustering, a
ConceptNet is a freely available commonsense knowledgebase and natural-language-processing toolkit which supports many practical textual-reasoning tasks over real-world documents right out-of-the-box.