I'm developing a wordpress template and that i now take some code that produces a loop to exhibit all posts although not full posts, just excerpts.

Can anybody help please?

All you need to know - with good examples - is here now: http://codex.wordpress.org/The_Loop

Make use of this code to create the excerpt in to the loop

<?php
    if(have_posts())
    {
        while(have_posts())
        {
            the_post();

            the_excerpt()
        }
    }
?>

The above mentioned will generate just the excerpt from the posts. If you want extra options like publish title, date, author and much more you need to browse the WordPress codex. http://codex.wordpress.org/Main_Page

Read more about the hyperlink gaved by songdogtech below