What are some Search Servers out there?

I wrote a long post about my experiences and features of all the engines I listed below but I scrapped it because formatting is a pita. But quite simply if you don't want to shell out money Solr/Lucene or Fast (now MSSE) is really about the best you can do.

Excluded because I have no experience of this product:
Seamark,

### Price High to Low

- Endeca,
- FredHopper,
- Mercado,
- Google Mini,
- Microsoft Search Server,
- Autonomy,
- Microsoft Search Server Express,
- Solr/Lucene

### Speed Fast to Slow

- Google Mini/Endeca,
- FredHopper,
- Autonomy,
- Solr/MSS/MSSE

### Features High to Low
- Endeca,
- FredHopper,
- Mercado,
- Solr,
- Autonomy,
- Lucene,
- MSS/MSSE,
- Google Mini

### Extensibility High to Low
- Solr/Lucene,
- Endeca,
- FredHopper,
- Mercado,
- Autonomy,
- MSS/MSSE,
- Google Mini

### Java API

- Endeca,
- FredHopper,
- Autonomy,
- Solr/Lucene

### .NET API

- Endeca,
- Solr/Lucene,
- MSS/MSSE,
- Autonomy

### XML API

- FredHopper,
- Mercado,
- Solr/Lucene,
- Autonomy,
- Google Mini (limited)

### Faceted Search

- Endeca,
- FredHopper,
- Seamark,
- Solr

### Natural Language Search

- Endeca,
- Fred Hopper,
- Solr,
- Mercado,
- MSS/MSSE,
- Autonomy,
- Google Mini

### Document Crawling

- Endeca,
- Mercado,
- MSS/MSSE,
- Autonomy,
- Google Mini

### ITL

- Endeca,
- FredHopper

### Merchandizing/Content Spotlighting

- Endeca,
- FredHopper,
- Mercado

### Distributed Search

- Endeca,
- FredHopper,
- Mercado,
- Solr/Lucene,
- Autonomy,
- Google Mini

### Analytics

- Endeca

### Platform x86 Windows

- Endeca,
- FredHopper,
- Mercado,
- MSS/MSSE,
- Solr/Lucene,
- Autonomy

### Platform x64 Windows

- Endeca,
- FredHopper,
- Solr/Lucene

### Platform x86 Unix Variants

- Endeca,
- FredHopper,
- Mercado,
- Solr/Lucene,
- Autonomy

### Platform x64 Unix Variants

- Endeca,
- Solr/Lucene

### Other

- Google Mini