Custom Scientific, Inc.
We provide optical filters, optical flats and other high-quality custom optics, with specialization in astronomy filters.
http://www.customscientific.com/

Arcotronics
EMI EMC RFI filters and interference reduction engineering solutions.
http://www.arcotronics.net

Electronic Specialists, Inc.
Electronic Specialists - ESP - Industrial Variac AC Power Line Conditioners, Isolation Transformer, protection, surge lightning suppressors, protectors, interference filters ...
http://www.elect-spec.com/

Centre Optics
Kiev Research and manufacturing Centre Optics produces optical filters, such as intereference optical filters, lenses, windows, mirrors and prisms.
http://www.optica-filters.com/

SI RNA - Small Interference RNA Resources
jobs, lab registry, news, forum - updated daily
http://www.si-rna.com

Ottisoft Software
Educational physics and astronomy software for high school and college
http://www.ottisoft.com/

RNA Interference at Journal Nature
RNA interference: A Nature Reviews journals web focus on RNAi - a selection of recently published Reviews, Perspectives and Highlights on this topic.
http://www.nature.com/focus/rnai/

Tyder Ltd
Provides digital filter design software which can produce specialised filters e.g. Windowed FFT, Optimal FIR filters, and IIR filters.
http://www.tyder.com/

Simple Filters
Easy to use filters for enhancing Photoshop and Paintshop Pro - Not available anywhere else!!!
http://www.btinternet.com/~cateran/simple/

Simple Filters
Easy to use filters for enhancing Photoshop and Paintshop Pro - Not available anywhere else!!!
http://www.btinternet.com/~cateran/simple/