Differences between postgres and mysql

the reason I ask is I have always used postgres at home and work, but my new
web host only has mysql :(

I want to know what sort of differences I will have in regards to
programming php/perl webpages using the database.

I current use sequences in postgres and understand this will be different in
mysql, so can you tell me what the difference will be and if there are any
other differences I should look out for.

Thanks in advance

Regards

Mark Cubitt