Artemis is a genome viewer available from Sanger Institute. Its a java based tool with a 3-paned interface window that depicts the genome at various resolutions. Alternating between the different resolutions is a bit tricky but once you get a hold of it shouldn’t be difficult. There is a also search tool that allows your to track down the particular feature that you’re looking for.
A great feature of Artemis is that it allows you to edit the sequence annotations and features. Although the tool isn’t perfect and is a bit finicky at times, it gets the job done.
Artemis supports the most common filetypes -EMBL, GENBANK, FASTA or raw format. Extra sequence features can be added in in EMBL, GENBANK or GFF format.
The best thing I like about Artemis is that there is a web version as well as an offline version, which means once you get used to it you can run it on or offline on any computer anywhere that has java.
Apollo genome viewer is another java based genome viewer and annotation tool. It is a part of the Gmod project which runs most of the online genome viewers. The tool came out of a collaboration between the Berkeley Drosophila Genome Project and The Sanger Institute.
Apollo has a similar set of features to Artemis provides, but I found the interface to be less user-friendly. But that’s just a personal opinion so you would be best to have a go at using both Artemis and Apollo and decide for yourself which is best. Again, the user guide will help you make best use of Apollo.
The NCBI Genome Workbench
The NCBI Genome Workbench is far more than just a genome viewer. As the name suggests, it is a complete and customizable workbench of tools that allow you to organize sequence data, which you can retrieve from NCBI databases or from your own files, for a project then view and manipulate them in a variety of ways. There is no online version available but downloading and installing NCBI genome workbench is quite simple.
The software allows you to view sequences as flat sequence files, phylogenetic trees, alignments and more.
The excellent zoomable graphics mode is the real strength of this package. It allows you to easily explore your sequence data at different levels of detail - individual genes can be viewed alone or in their genomic context and can be BLASTed straight from the graphical view. A nice set of alignment analysis tools is also available and BLAST and analysis results can be saved to your project making this a great way to keep track of your sequence data and analyses.
The tool supports quite a number of file formats, and I had no problems working with FASTA and most other file formats however when I tried to import the complete 1st chromosome of Dicyostelium which is in a GFF3 format the program kept crashing repeatedly, so clearly some bugs still need to be ironed out.
The NCBI genome workbench is a great idea, and provides a number of useful tools that make the program a must-have but the interface is a bit clunky and takes some getting used to. However, the site has a comprehensive set of instructions/tutorials to help you get up the learning curve quickly.