Ruling on making programs that banks can use in giving riba-based loans
Question

                I have a project for making electronic programs which transmit information on riba-based loans between banks, so that they can find out about the loans that a person has taken out before giving him a riba-based loan. But this program does other things besides that. Is this permissible?.
Praise be to Allah.
    If this program can be used by the riba-based banks to get 
    information about those to whom they are going to give riba-based loans, 
    then it is not permissible to sell it to them, or to work on it, because 
    that is helping in sin and transgression, and Allaah, may He be exalted, 
    says (interpretation of the meaning):

    “Help you one another in Al‑Birr and At‑Taqwa (virtue, 
    righteousness and piety); but do not help one another in sin and 
    transgression. And fear Allaah. Verily, Allaah is Severe in punishment”

    [al-Maa’idah 5:2]

    And the Prophet (blessings and peace of Allaah be upon him) 
    said: “Whoever calls to misguidance will have a burden of sin like that of 
    those who follow him, without that detracting from their burden in the 
    slightest.” Narrated by Muslim (4831). 

    There is a stern warning concerning riba, and curses for 
    those who do it, write it down and witness it; this is a deterrent to every 
    wise person from getting involved in it or helping in it. 

    Allaah, may He be exalted, says (interpretation of the 
    meaning):

    “O you who believe! Fear Allaah and give up what remains 
    (due to you) from Ribaa (from now onward) if you are (really) believers.

    279. And if you do not do it, then take a notice of war 
    from Allaah and His Messenger but if you repent, you shall have your capital 
    sums. Deal not unjustly (by asking more than your capital sums), and you 
    shall not be dealt with unjustly (by receiving less than your capital sums)”

    [al-Baqarah 2:278-279]

    and Muslim (1598) narrated that Jaabir (may Allaah be pleased 
    with him) said: The Messenger of Allaah (blessings and peace of Allaah be 
    upon him) cursed the one who consumes riba and the one who pays it, the one 
    who writes it down and the two who witness it, and he said: they are all the 
    same. 

    So beware lest you be helping in this grave sin. 

    We ask Allaah to protect you against that and to make it easy 
    for you to find halaal and blessed ways of earning a living. 

    And Allaah knows best.