ScottGu’s Blog – Dynamic LINQ (Part 1: Using the LINQ Dynamic Query Library)

…Both the VB and C# DynamicQuery samples include a source implementation of a helper library that allows you to express LINQ queries using extension methods that take string arguments instead of type-safe language operators. You can copy/paste either the C# or VB implementations of the DynamicQuery library into your own projects and then use it where appropriate to more dynamically construct LINQ queries based on end-user input.
weblogs.asp.net/scottgu/dynamic-linq-part-1-using-the-linq-dynamic-query-library

Dia – Free software for creating technical diagrams similar to Visio

Dia is roughly inspired by the commercial Windows program ‘Visio,’ though more geared towards informal diagrams for casual use. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams.
wiki.gnome.org/Apps/Dia

Another free alternative to Visio is Openoffice draw. Read more here: https://chase-seibert.github.io/blog/2009/03/26/openoffice-draw-vs-visio.html#