This is a thorny subject and in my experience a solution designed by someone else for their local use is rarely accepted elsewhere since the processes/business logic used at your location is going to be different (and people loath to change, in some cases that may be justifiable for specific reasons).

I assume you are asking for a solution to manage samples being submitted for sequencing (and not sequences themselves).
Sierra is a LIMS used by Babraham Bioinformatics Group and available as open source. I am sure you will get lots of other suggestions.

Nowadays, you might be better off using a general Content Management System or Framework, eg. Drupal. Using Drupals Fields and View you can make flexible data types, forms, and reports without (mostly) programming. We have built a full RNAi-LIMS like that. CMS handle a lot of stuff for free, like authentication, file management, etc. and you will be much more agile in adapting the system to the needs of users (add a field = three clicks). Use autocompletion for field content? A module, it's already there.

Also, if you just do it for good-will, I wouldn't recommend to do it yourself from scratch. Think about these points:

• You will be administrator for the system for life, nobody might be able to take over
• People will want to project their frustrations about the system to something, it is better this is not only you, but so you can share the blame ("that's a bug in Drupal, nothing I can do" )