Accordance is a Bible study program for Apple Macintosh and iPhone , and now Windows developed by Oaktree Software, Inc.  Reviewers Consider It has premium program. 
ALTHOUGH Originally written Exclusively for the Mac OS (And Then iOS ) Accordance HAS-been now released (October 1, 2013) in a Windows-native version, ALTHOUGH It was available prior to this by using the Basilisk II emulator.
The program is used for both private and academic studies. The translators of the Holman Christian Standard Bible , completed in 2004, used for comparative studies, comparisons and instant searches. Commenting on the use of the Accordance, the HCSB editor Ed Blum said, “This project is more computerized than anyone else has ever been able to do.” 
OakTree Software, Inc. is based in Altamonte Springs, Florida , USA. The company has focused on areas of special interest, particularly the study of Biblical texts .
OakTree Software claims three specific goals:
- Offering innovative and powerful features which can not be found anywhere else
- Providing the most intuitive, elegant, and easy-to-use interface possible
- Providing a wide range of useful resources like texts, dictionaries, & commentaries, for Bible study. 
Roy Brown, OakTree Software’s President and Application Developer, first published in 1988. ThePerfectWord was later bought by MacBible and renamed MacBible. By the early 1990s there was a number of good general Bible study programs for the Mac. However, it seems that the author of this paper will be able to make it easier to engage in more sophisticated types of Bible study, enabling scholars and pastors to do in-depth analysis of the original Greek and Hebrew texts of the Bible. Accordance 1.0 was released in February 1994, and welcomed for its power and ease of use. 
A version of Accordance 5.0 rewritten to run natively under Mac OS X was released at the start of 2002.  The company has continued to add and improve features, such as the native Quartz rendering system. Version 8 was released in May 2008 and introduced a universal binary for Intel-based Macs. Version 9 was released in September 2010, version 10 in 2012, and version 11 in 2014. 
Accordance for iOS was released on December 30, 2010 as a free app for iPhone, iPod Touch and iPad. 
The program is centered on the Biblical text,  but has many additional texts. There are many optional modules, detailed study tools for the original Hebrew and Greek, commentaries and reference dictionaries, with a unique cross reference system to interconnect the Biblical text with entire libraries of ancient extra-biblical material  .
Some modules available include:
- Mishnah , Targums , Pseudepigrapha , Josephus and early Christian writings such as the Didache 
- Biblia Hebraica Stuttgartensia with the Groves-Wheeler Westminster Hebrew Morphology 
- Louw & Nida Semantic Domain Lexicon 
- GNT Robinson Byzantine
- Dead Sea Scrolls 
- Atlas Bible and Bible Lands Photo Guide 
- Comprehensive Cross Reference interactive module for Dead Sea Scrolls, Josephus, Philo, Nag Hammadi Library, Pseudepigrapha, Old Testament Apocrypha, New Testament Apocrypha, Plato, Pythagoras, Dhammapada, Egyptian Book of the Dead, Tacitus, Talmud, New and Old Testaments, Apostolic and Early Church Fathers 
Although the product has many modules, it is simplified by packaging these into ” Collections ” (which have replaced all of the earlier “bundles” and “libraries”).
It is one of About.com’s top 10 Bible programs. 
- First Bible Software – A Comparative Overview at Bible Software Review, December 29, 2006
- Accordance 8 – The Best just got Better , August 6, 2009
- Review of Accordance 6 by the Society of Biblical Literature
- Accordance 5.5c review in Macworld
- Independent reviews listed on Site Agreement
- ^ Jump up to:a b Oaktree Software Archived July 23, 2011 at the Wayback Machine . on company site
- Jump up^ “E-Search the Scriptures” . Evangelical Fellowship of Canada . May 2004. Archived from the original on 2011-01-02 . Retrieved 2011-01-02 .
- Jump up^ Rebecca Barnes (2004-04-16). “New Holman Christian Bible Standard offers fresh translation” . Central Church. Archived from the original on 2011-01-02 . Retrieved 2011-01-02 .
- Jump up^ Accordance: Historyon company site
- Jump up^ Bible Accordance software now Mac OS X native, January 14, 2002,Macworld.
- Jump up^ Software, Accordance Bible. “History” . Accordance Bible Software . Retrieved 2016-10-05 .
- Jump up^ Buzz: Acquired for iOS Now Released, Oaktree, December 30, 2010
- Jump up^ User Interface Concepts ArchivedJuly 23, 2011, at theWayback Machine. on company site
- Jump up^ Fairchild, Mary. “Top 10 Bible Software Programs” . About.com . Retrieved 2 January 2014 .