The ChristenUnie people are more deeply religious. Sometimes they have suprisingly liberal positions. The CDA also incorporates the Catholics, and the Christenunie is formed out of a number of smaller, less mainstream protestant churches.
EenNL is sort of a split of the Fortuyn party. Fortuynism is the politics of the murdered Pim Fortuyn. It's a kind of patriotic populism with a libertine twist. Sort of like Sullivanism.
The VVD was being too middle of the road for Wilder's tastes under the leadership of Jozias van Aartsen, which is why he went away. He may also have daydreamed about making a similar kind of breakthrough as Fortuyn managed, but he doesn't have the required charisma. The VVD has since veered right and back left again. Currently, they're still a bit more right-wing than they were under Van Aartsen, but also more modern.
A liberal in the Netherlands is someone in the general tradition of Adam Smith, John Stuart Mill and John Rawls (in Dutch history Thorbecke is the most important liberal, certainly from the VVD viewpoint). There are a lot of different viewpoints expressed in that tradition. Generally, liberals are modernist in the sense of believing in progress, areligious, and most believe in the free market. Liberal doesn't have the left-wing connotation that it has in the US (don't know how it is in the UK), nor the libertarian connotation of neo-liberalism (although both liberal parties are pro-market, only a wing of the VVD is really neoliberal).
Specifically, the D66 party came out of the progressive movement of the '60s (as the name indicates), and the VVD is a continuation of one of the oldest political parties, after several splits and recombinations. The VVD is something like the party of business and the middle class. D66 is on life support. There is a new party called LibDem, but I don't know if they made it.
The Liberal party and its Whig predecessor, opposed royal absolutism and promoted the gradual reform of the political system, which eventually led to democracy. Under its great nineteenth century leader. W.E. Gladstone, the party slogan was 'peace, retrenchment and reform' - by which was meant no imperial adventures (such as in Afghanistan), low public expenditure (although the election promise to abolish income tax did not bring Gladstone victory when he tried it) and reform (votes for the working class).
The old programme was rather eclipsed by the start of the construction of the welfare state. Later stages of this programme were implemented by Labour governments, but a lot of the ideas came from Liberals like William Beveridge.
The more right wing strains of British Liberalism drifted off and joined the Conservative Party between 1886 and about 1950.
British liberals regard the Labour Party as the competition and the Conservatives as the opposition, but try not to be characterised as centrists.
Personally, I think the VVD is gradually becoming more neoliberal, and I also suspect Rutte is a neoliberal trying to hide he is.
Interesting that there are two different answers to Migeru's questions and they are both correct...
I don't know about Rutte, I think he's going to be pragmatic. Sometimes he says something that sounds neoliberal, but he also uses populist left-wing rhetoric. So it's kind of hard to say who the real Rutte is, but he sees himself as being on the left wing of the VVD. Under Verdonk the VVD would really have had a classic Thatcherite neoliberal agenda, so that's what I meant by saying they veered right and then a bit back to the center again.
