Different versions of Arabic Qur'an

[Tanzil.net](http://tanzil.net/wiki/Medina_Mushaf) writes: >The Medina Mushaf ... publishes the holy quran according to **three famous narration**, i.e., *Hafs, Warsh, and Ad-Duriyy.* The Quran text provided by Tanzil is based on the Medina Mushaf, narration of Hafs. From there I came to know tht currently there are 3 there different versions of Quran. Digging up a little more, I found that there used to be several 'authentic' versions of Quran: >Even though the Hadith spoke of 7 versions, **Al-Tabari** concluded that **8** of the existing versions of the Quran were ‘authentic’ (later scholars increased this **to 10**) [[source](http://www.free-minds.org/which-quran)] Also, according to aforementioned source, ***Verse counts** for Hafs are 6236, while Warsh records 6214.* That source also lists some differences in these two Quran, and even more can be found in this [pdf](http://www.free-minds.org/sites/default/files/WhichQuran.pdf) . So, contrary to our firm believe that there has been no alteration in Quran, there are different versions of Quran. So which Quran should we follow and why? And why should there be different Qurans to begin with ? --- Update === After reading various suggestions, I came across this hadith: >Abû Qilaba narrated: >>It has reached me that the Prophet(P) said: "The Qur'an was sent down according to seven ahruf: command and prohibition, encouragement of good and discouragement of evil, dialectic, narrative, and parable." However, the [article](http://www.islamic-awareness.org/Quran/Text/Qiraat/hafs.html) went to explain it like this: *[use CTRL+F to jump into exact place]* >The forms matched the dialects of following seven tribes: Quraysh, Hudhayl, Thaqîf, Hawâzin, Kinânah, Tamîm and Yemen. The revelation of the Qur'an in seven different ahruf made its recitation and memorization much easier for the various tribes. Again reading reading further, we can find that : >Following the distribution of the official copies, all the other ahruf were **dropped** and the Qur'an began to be read in only **one harf**. Thus, the Qur'an which is available through out the world today is written and recited only according to the harf of Quraysh Why do we **still have many ahruf then**? It would be even more helpful if you could explain **how the ahruf map to various dialect**.